Yeah, that happens to me all the time.
I use several tactics to try to identify songs:
1. check out the stations web-site. Often they'll post their playlists on-line.
2.
www.towerrecords.com I use it as a reference page. You can often listen to sample clips from almost aany artist.
3. As last resort, if you can catch a unique phrase sung in the song, and remember a sentence or two of it, jot it down, then actually go to altavista.com or one of the more specific search engines and enter the phrase with quotation marks around it. I did this to find the Olive song, Outlaw. The word Outlaw never appears in the song, but I had the phrase, "Couldnt you have told me before, I would have loved you so much more." I entered that exactly and It took me to some stalkers web page that is obeseesed enough with olive to actually put her lyrics on his page. But hey, I got the name of the song, and then went to limewire and downloaded it.
Hope it helps.