iTouch app suggestions?

Anyone have particular iTouch/iPhone apps they especially recommend? (Yes, Santa Claus/my parents were very good to me!)

I'm already planning to get:

* Stanza
* Toodledo's app
* Snowmint's Budget app
* that free level app, even though it doesn't actually work that well, because the concept is just so cool

I'm interested in:

* a basic astronomy app (I used Planetarium on the Palm and found it a little challenging to use but good as far as the star maps and planet locations went) * a basic checklist that handles multiple lists (mainly for trip packing, but also useful for party planning; Simple Pack may be what I want, but we'll see)
* a solitaire app that includes a two-deck version of Spider
* possibly a simple database, though in practice I'm not sure I'd use it that much
* in the massive wishful thinking mode, a decent genealogy app (actually, I really want The Master Genealogist for Mac with a coordinating iTouch app,
neither of which is ever happening)