A couple of options....
1) IPOD: I have an 80gb IPOD (classic) with a suite of portable apps on it;
- Firefox (has all my bookmarks)
- Thunderbird (email)
- Pstart (pop up menu)
- Skype
I can plug this into any PC and use my email/browser/skype
2) IPOD Touch: my wife has an IPOD...