Crackberry here.

Additions/changes to the list provided by Cheryl.
The OTA antenna - I've seen the terk-5 for anywhere from $27-$40. There are probably others that work fine, that is just one that somebody on a forum told me about.

The ph meter should be about $39, the tds is more...I think around $60. Combos are well over $100. How much sense does that make??

The harmony remote costs around $100 so too much.
Other possibles: Breadmaker, cordless mice and keyboard, lowe's gift card, boston acoustic satelites for the rear speakers (prolly too much though...I think they're over $100), extra ram for the puter, fish (australian rainbows...might be tough to wrap though).

That's all 4 now.