Which Flash Memory drive to get?

I don't know if I'll be using 8 GB of RAM, but it could come in handy. I found them for a bargain. The 8 GB ones are for only $80, while the 4 GB Sandisk is for just $30. Say if I go to a friend's house and dump their music on mine? Or run out of space. The Memorex one look stylish and is made for Vista. Sandisk(dont' see Vista on it, I'm sure it can do it though) is the better deal because it's only $30. I don't know about Sony, don't see a keychain attachment on it. So what do you guys think is the better deal? Does memorex look like a good deal, or sandisk?


http://www.sonystyle.com/webapp/wc [...] &langId=-1

http://www.tigerdirect.com/applica [...] TC-BIZRATE

http://www.radioshack.com/product/ [...] =techSpecs