The folks over at gioga23.com has found out about an unknown hidden feature of iPhone OS 3.1 (and 3.1.1 for iPod touch) which brings full video editing capabilities of iPhone 3GS to the original iPhone, iPhone 3G and iPod touch.
In order to get this feature to work, simply save a video attachment from email into your camera roll and start playing it. You’ll now notice an extra editing bar appearing at top which will enable you to trim videos like iPhone 3GS !
For those of you who are on iPhone with jailbroken firmware 3.0 can try out this guide to enable full video editing capabilities of iPhone 3GS in iPhone, iPhone 3G and iPod touch, running firmware 3.0.