Well, I would consider chocolate obvious but just in case you don't, I'll mention it - don't forget chocolate.
Let's see, what else - since I don't know what's obvious to you I'll list a few more...
~ extra memory card for digital camera
~ calling card in case your hotel charges outrageous amounts for local calls and your cell phone battery dies... though that probably only happens to me!
~ throat lozenges in case you start to lose your voice from yelling every time you see another SCSer.
~ a sorry your team didn't win card for Pam (just in case - things aren't looking very good right now but my boys are know for their come from behind wins!)
That's all I can think of right now.