We mainly use this for checking travellers reviews.
World Wide Opportunities on Organic Farms (WWOOF)
Great if you want to volunteer on organic farms. Haven't had a chance to use it yet, but we've heard great things from people we've met.
The best and cheapest travel/medical insurance. You have the option to purchase while already travelling abroad. This option is rarely offered by many travel insurance companies.
It's basically like Craigslist where you can find the latest ads for apartments, rooms, jobs, etc.
Most used for keeping in touch with family and friends.
Currency converter which is current and refreshes every minute- very useful!
I think we've used this the most in Brazil. No one speaks English.
For finding out the names of all the awesome tunes we've heard along the way. :)
Hotel Wifi Test
You can find hotels around the world with the fastest wifi. Pretty sweet!