Update to my last post - the X10 8-in-1 remote I referred to is available from X10.com for $24.99 ([Link: x10.com]), and based on their almost-perpetual promotions, you can get $20 off, plus other free stuff. If you can't figure it out from their front page, sign up for their mailing list, and you'll receive instant discount vouchers on a regular basis. I don't know how these guys make any money, but that's probably another story.

Anyway, almost every key on this remote is programmable, it has a shift key making for relatively intuitive reprogramming, and as a bonus can control X10 stuff if you have the basic X10 starter kit (very cheap). I have found that if I try to program all the Tivo controls onto one function (e.g. cable box) I run out of memory (I think - the LED blinks rapidly), so I had to put a few functions on another function (e.g. Aux1), which seems to work fine.