You need not look for a WiFi connection (or the super fast EDGE network) to show your favourite videos to your friends, instead you can save those kewl Youtube videos onto your iphone directly! MxTube does the trick! These 3rd party apps on the iphone (Read Jailbroken iphone) has truly discovered the iphone. Video downstairs
But wait, there’s more to it now. Apple has just released the iphone SDK with a number of companies (EA, AOL etc) testifying that it will bring some of the best apps for the iphone shortly.