The following apps are absolute essentials to anyone with, or thinking of, getting a Touch. IMHO of course
1. Battery Status
This includes omap clock so you can overclock this slow device...I've been overclocking at 234 for a while now...no problems
2. Pocket CM
This is a contact manager, sort like the iphone, with finger scrolling, search by category, city, favorites, etc...
3. PCM Keyboard
Also from the maker of Pocket CM, this keyboard is what I've been waiting for ever since I got the touch...it's predictive (optional) precise, and fully customizable (aserty, qwerty, lkouyt, etc...) you simply have to play around with it to believe it...in fact, watch this
For clarification, I have no relation to any of these companies, even though I've written about these in other places...and anyway, all these apps are free, but they have improved my "techno life" so I hope they'll do the same for you...
Please feel free to post your comments about these and also other "essentials" for you because if they are anything like these 3...i want em