More glad you got the T3 now, huh?! See - it all works out. Congratulations and welcome to the world's best forum!!
I also went from a 505 to a T3 - and compared to our 505s, you'll LIKE the battery life on the T3. If you haven't already, when you get it OPEN THE BOX, put on the charger, DON'T TURN IT ON, and charge that baby up for 3-4 hours. Please listen to me and don't listen to anyone else on this one!! Resist the temptation lad . . . resist the temptation. Charge that thing up FFFUUULLLLLL.
The initial charge is important, and don't be shy about sticking on the cradle during regular "computer time," too. I try not to leave min hooked up for more than 4 hours at a stretch. Also, don't be afraid to run it quite a ways down AFTER the first charge, and then OOOMPHHH it back up again with a good 3-4 hours. Get that initial thing "whacked" with a good charge. Disable Bluetooth and Beam Receive, lower your brightness to AT LEAST HALF (I'm VERY happy with about 25%) - and your battery life will be very, very good.
As for the SD Backup Card,
1. I had one and when I looked at the "security" of it I laughed - it's a joke. Used it for a year, but wouldn't again even if it worked.
2. I don't think it has the capacity to hold what you'll be backing up on the Tungsten - depending on the "vintage," it's either 8MB or 16MB - more than likely too small to do the job.
Arguments (friendly of course) rage on here all the time about backup programs, and there's lots of BIG fans of BackupBuddyVFS and BackupMan. TealBackup is new & allows for multiple timed backups and ENCRYPTION and Selected Files. I'm not using it presently, but will as an auxhiliary to CardBackup (I prefer the latter since it's been dependable, and that's REALLY endorsement coming from me since I'm such a Teal nut). REAL protection would be two programs from two makers with their own files, but I REALLY TRUST jkware's "CardBackup."
My choice is jkware's CardBackup (err, that would be me and a couple of others) because I've actually TESTED it with 2 DELIBERATE hard resets, and two that were not, and it's flawless!! I have an SD256 Panasonic, and have CardBackup do TWO backups to TWO different files - one at 5AM with auto-off, and the other at 5PM with auto-off DISABLED in case I'm working on something. You can have up to 8 timed backups, as well as "any time you want." Backup of most "recently added file changes" with CardBackup takes less than 6 seconds; full restore is REALLY quick and you can select files NOT to back up. It's $11.95 and I think it ROCKS.
Any good backup proggie and a large SD Card would be preferable in my view to the one you've got (probably too small anyway) or a "dedicated" Backup/Secur Digital Card" bundled by PalmOne (pricey and not worth it). Assuming you put 20MB on the handheld, then TWO backups would be 40MB - so a 256MB card affording a "net" 243 meg is already down to 200MB - but that's quite a bit at least for me. 512s and 1GBs are coming down all the time, so you might even want to get one of those and "really be set."
Hope this helps and once again, welcome and congrats.