This weekend, some of the best and brightest minds from 25 locations all over the globe will get together for an event called “Random Hacks of Kindness” to collaborate on solving huge global challenges.

Big named companies and organizations like Google, Microsoft, Yahoo!, NASA, HP, and the World Bank have created this event to invite experts in global issues to collaborate with talented developers and engineers. This year’s hackathon’s attendance should be impressive, according to the venues we spoke with.

Each location is focusing on solving different problems, with San Francisco’s local event taking a look at bicycle commute mapping and emergency drinking water. In San Francisco, Voxeo Labs will be the host. This year, events are being held in cities like Philadelphia, New York, London, Toronto, Tel Aviv, and Zurich. For a full listing of events, check out the Random Hacks of Kindness site.

In recent years, Random Hacks of Kindness events have made an impact on social good by turning out mapping tools to report bushfires, apps to connect food stamp recipients with sources of fresh produce, and visualization tools around landslide risks.

Johnny Diggz, Chief Technology Evangelist for Tropo and founder of Geeks Without Bounds says about “RHoK”:

When disaster strikes, more than ever, people need to communicate and we are excited to see RHoK developers use Tropo to help in crisis situations.

Tropo is a service similar to Twilio, which lets you embed calling and texting features into your own app. Imagine the possibilities for disaster related communications utilizing that technology.

This weekend during Random Hacks of Kindness, some of those possibilities and ideas will become actual working applications thanks to thousands of developers and thought-leaders worldwide.

➤ Random Hacks of Kindness

If you’re a Nirvana fan, you’ve probably spent hours upon hours scouring the Internet looking for every piece of footage available on the band. The site A World Of Nirvana has taken the grunt work out of enjoying rare concert footage of the band from the entire life of their career together.

The app uses the Google Maps and YouTube APIs to collect concert footage broken up by each year and pulled and shown on the location the event happened.

Simply choose your year of interest, pick a location, and the video is shown directly from YouTube. Some of the videos are super compressed full versions. The quality of the videos aren’t the best, but there are shows that I’ve found here that I didn’t know existed on YouTube.

Even if you’re not a huge Nirvana fan, you’ll find surfing around the map and picking a random show to check out to be fun. Hearing the band’s sound get tighter over the years is impressive for any fan of music to watch.

➤A World Of Nirvana

One of my favorite things to do online is chat. Real-time chats haven’t been done well since the old aol chatroom days where you could enter a room based on the city you were close to, or an interest that you had.

Since aol, apps like Yobongo have tried to bring chat back with real-time serendipitous chats based on your location.

Today a simple app called “Sirkel” was released.

Set your chat Sirkel

By dragging the slider up and down on the right hand side of Sirkel, you can choose how much of the world you’d like to chat with. Your default circle is set to 3 miles.

You log in with your Facebook account, and the app asks you for your location. Once you get going, it’s kind of neat to see new people pop up on the map.

Chatting through your browser

Since Sirkel kept things simple, there is nothing to download. By clicking the photo above the red dot when someone pops up on the map, a chat is started with them. The chat interface is clean, and lays nicely on top of the map.

I could see leaving Sirkel up on my extra monitor, glancing at it once in a while to see if anyone is active. What we miss on Twitter and Facebook is real-time interactions with people that we don’t know. While this might not be something for everyone, it is a nice way to chat outside of your normal circle.

Considering that you can drag around the map, it will be interesting to see which areas embrace Sirkle, if any. The only downside to Sirkel is that there is no “friends list”, so if I chat with someone I have to remember their name, otherwise it’s likely that we’ll never talk again.

Try chatting outside of your default 3 miles, and see who you meet! Since the app requires you to login with Facebook, Sirkel won’t end up being rowdy or crude, since peoples real names are coming along with the incoming chat requests.

People from all over the world have tapped the “check-in” button on the foursquare app. The foursquare community team put together a video based on a call for check-in clips just a week ago.

They asked foursquare users to get creative on where they checked on, and film themselves doing so. The company must have gotten a lot of entries, since it had enough for an entire video in just seven days.

The company says that this is their first “#4sqVid”, so you may have more chances to get your check-in featured in the near future.

Here’s the video, and be sure to watch the end where foursquare co-founder Naveen Selvadurai attempts to deliver his lines with not much luck.

It’s easy to forget that foursquare has so many users, since we only see the people who are in our own city or watch our friends in other cities. foursquare was actually very helpful in my visits to London and Paris in the past few years.

Where’s the coolest place that you’ve ever checked into on foursquare? Tell us in the comments.

Apple has set up a tribute page for its former CEO Steve Jobs, who passed away this month. The day Jobs passed, the company offered an email address for anyone to send their words and thoughts to Apple about how much Steve Jobs meant to them. At that time, Apple didn’t tell us what it would do with the emails, but this memorial page is what has become of them. The company has received over one million responses.

A word cloud has been published using the words we’ve sent to Apple about Steve Jobs, and it’s extremely touching.

The top two phrases used in emails to Apple about Steve Jobs, according to this word cloud, were “Apple” and “World”. Reading some of the emails ourselves, we can see that people identified the work Steve Jobs did at Apple and how he helped change the world with his ideas and products during his tenure at Apple.

Some of the other most used phrases in these emails were “Thank”, “Family”, “Rest”, “Peace”, “Change”, as a lot of us hoped that Steve Jobs could now “Rest in Peace”, and that we wished his family the best with our deepest condolences.

Did you send an email to Apple about Steve Jobs? If you haven’t, you still can by sending your thoughts to: rememberingsteve@apple.com

Entering the search term “World Cup” in Google replaces the familiar “Goooooooooogle” graphic with the more appropriate “Gooooooooooal!”