A Song is like a Time Machine

I woke up with a song in my head this morning.  The song was "Long Goodnight" by The Get Up Kids.  I tend to be a sort of cave man when it comes to songs being stuck in my head.  It's like I still don't quite get it that, at the touch of a button, I can listen to any song I want at any time.  But, for some reason, this morning that idea clicked and I used good old You Tube to play the song.
I listen to my iPod quite a bit when I am doing things around the house but it is typically whatever I am currently listening to.  Not counting a few random Pandora visits I rarely listen to The Get Up Kids anymore.  I packed it away, along with my "Boys Lie" t-shirt, pink suede converse and old journals.  So the song came on and, just like that, I was 20.  I wasn't in my kitchen making breakfast and packing lunches.  I was with my best friends, driving in my Jeep.  Singing with my cousins.  Doing all of the things that I did as this song and album served as a soundtrack for, gosh, nearly 2 years.
It's not that I am not happy in the present, but it really was nice to hear a song and be immediately transported, if only in my thoughts, to a different time.  

What song/album has this effect on you?  Please share, I really would love to hear :)