USB Flash drives - Patriot and Corsair have been good drives for me, considering the abuse I've given them. Performance is especially good on these:
Corsair Flash Voyager - though the largest ones have had many complaints of being way too slow.
Patriot XPorter - the 64GB is REAL nice. It's all aluminum casing, even feels like quality. From my experience with that one, I'd say it'd be difficult to break. I've got the 32GB one personally, and another "partner" in our church media ministry is now using the 64GB model. Eventually, I'll have to get that one for myself - the Lord willing, and I actually get enough spare dough again.
When you look at them, I'd suggest looking for tests that show supposed durability and speed. Also, I'd personally stay away from the ones that force you to use some sort of autorun software. It can be buggy, and I remember one fella who got one (don't remember for sure, but it may have been a Sandisk Cruizer), and brought it to church. He swore he got it to work correctly at home, but the thing actually made our church media PC crash. I was able to boot it right back up, but Windows actually froze b/c of that one - annoyed me to no end. Actually, he had 2 in a row with the same/similar software, both with problems. He later got a PNY thumb drive, and I was blown away by it's performance, and no extra software.
Basically, in my opinion, for a flash drive, I'm not looking for software - just storage. If I really want to run software off of it, I'll get that separate, usually free - such as portableapps.com.
Methods of backup - I'd suggest NOT using a flash drive to put restore points on. I'd use it just to strait back up important documents and such. Basically I'd not use a flash drive for anything that would have very many read/writes of data. I've had to replace at least 1 Corsair Flash Voyager, actually 2 I think - different sizes, and I think I may now have to replace my Patriot Xporter 32GB.
One test I read of the Xporter XT before the 32GB Xporter Magnum came to market showed a test comparing something like 10 or 15 flash drives. The only drive that could keep up with the Patriot was a Lexar Lightening 2GB or 4GB SLC flash drive. 99% of the flash drives on the market now are MLC - it's TONS cheaper that way. But MLC isn't as fast, generally, as SLC, and it's not as reliable. If you happen to be able to find an SLC drive, reasonable, and it'll fit your needs - storage space-wise, then go with it.
From a backup perspective, being easy, and being a full system back-up, my personal suggestion is to use Acronis True Image, and run the backup process through it to an external hard drive, eSata if possible. And there are drives out there which will automatically power down with no activity and/or when your Windows PC is shut down. I think that feature alone would be important for a no-effort backup. If the thing is powered down, it isn't spinning, so your chances of data loss on that drive are greatly reduced.
Another option to look at is online backups - there are just too many out there to mention them all. Mozy has one that many say is good, but I don't know of a single service that hasn't had at least some griping about it. It's still a fairly new idea. But it would be a good backup for important documents - I mean backup of a backup, so to speak.
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"If to err is human, then I must be some kind of human!" -Me