Skip a track not in iTunes

I use bytecontroller a free app which lets you keyboard shortcut play/pause/back/forward. And it has a menu bar controller as well.

Definitely what you're looking for .

 

If you want a few more hot-key features (volume, hide/show iTunes, rate songs, etc.) and a track indicator to boot, € 5 will get you a license to Synergy, which works great for me.

 

There's a slightly long-winded approach using just standard keyboard commands.

Hold Command down and press Tab until you get to iTunes. Let go of the keys. Command and Right Arrow or Command and Left Arrow will skip forward or back a song. Command and Tab back to the program you were in.

Like I said a bit long winded!

 

Bytecontroller lets you adjust volume as well .
And if you want to save 5$ in style you could use the quicksilver and GrowlTunes combo.
Quicksilver to start play songs or add to party shuffle (F1 searches for song title, F2 artist for artist here).
Quicksilver and GrowlTunes to get info and rate songs. All with done with a nice and easy keyboard combo .

 

itunes doodad. (too lazy to look up the url.) it's perfect--you can do all kinds of basic itunes navigation right from the menu bar. it's not a key combination so you'll have to click your mouse. also, it's free! i've been using it for several years now. not sure if it works on 10.4 cuz i'm still 10.3...