You're spot-on! Those were 2 that I was interested in. The top one actually has a keyring hole in that black plastic base, but it's such a short drive that it's really meant to leave in a laptop, so it's hard to pop it in and out.Like Hectic, I use either SanDisk or PNY.
I normally don't go by reviews as there will always be someone that has a complaint about something.
You've probably seen both of these, but just in case:
I think the bottom one will fit your needs as the first one doesn't look like it will fit on a keychain.
The bottom one would be perfect, but the 2 things reviewers said were:
1) it gets really hot, which may make it more prone to crap out, and
2) people complained of slow transfer speeds.
I could probably live with both of those (possible) issues, but I wouldn't want it to die on me.