@gt3000bk:
Boy oh boy that's a question that will start a debate raging! Ha ha ha!! Perhaps a good one . . . so I'll give you my 2 cents and let the "fur fly" from others that think I'm completely nuts and will vehemently swear by the very thing I denounce.
I had 2 SanDisk cards that went bad. Quickly. I ONLY use Panasonic (and have a 256MB I've had almost 3 years with a LOT of use and no problems, despite even defragging it via my PC).
My Nikon D80 digital camera also uses Secure Digital - and in that I have several Lexar 60x 1MB cards that have been flawless. Now 2GB is lower in price ($140 down to $59, and 133x write speed) I'll step up to those in my Nikon, but will keep the Panasonic in my T3 since I only fill around 80MB of the 256MB as it is.
My "2 cents," then, would be stay away from SanDisk. I believe Lexar make certain SanDisk cards - but you can't find that out til you open the packet - and twice burned, I wouldn't buy another one and "throw the dice."
My recommendation then from personal purchasing would be either Panasonic or Lexar Hi-Speed - although as Mooseman points out its ability might bottleneck at the Palm's writing ability. I also wouldn't buy a bigger card than you can foresee using, as camski pointed out. If you plan on 300MB, then a fast 512MB should be fine; I wouldn't use a 2GB unless you're planning on using at least half of the alotted size.
Now wait . . . someone will swear by SanDisk! It's all personal, but I've made up my mind and can pass these recommenations on to you as "my experience only."