multiple libraries in iTunes possible?

I've seen articles on how to move an entire library to an external drive, but what I'm wondering is if I can "sub-divide"? In other words, what I'd like to do (if this is possible) is to store my podcasts on my laptop (where iTunes is), but store everything else on an external drive.

Here's my thought. I travel a good bit. My music on my iPod stays fairly static, but my podcasts change more frequently. I'd like to be able to update my podcasts while on the road, but don't care as much about updating music as frequently (I can do that when I'm home).

Also if I can do this, and I do a sync without the external drive connected, will iTunes be able to updates podcasts but leave my music alone? Or will it freak out that it can't find the music (because it can't find the external drive)?

BTW, in case it matters, I'm one of those nasty PC users your mother warned you about.

 

Don't everybody answer at once -- it's too confusing!