I'm often disappointed when they tell me someone's on a song though. Skiba's on a Rise Against song, but he just did like "whoa-ohs" or whatever.. couldnt tell it was him. I'm with ya I guess... but guest spots should be more substantial and noted properly lol.
yeah seriously if some one didn't tell me tim mcilrath was on that one thursday song, I would have probably missed it. there are tons of other examples i can think of. it doesn't help that when these songs have videos, the guest artists are like NEVER in them.