Ok, so the short version is I have a friend who's asked me to show him some basics. I'm starting him off on basic riffs, chords, and scales, but he's really anxious to 'jam out'. I'm already planning to teach him Wish you were here and some basic 12-bar blues stuff, but I'm a little light on ideas for songs that work well with both acoustic and electric. Please bear in mind that while I've been playing and practicing a while, he's still completely new, so I'd like stuff that, at least for the electric bits, are fairly simple.

Thanks in advance!
Burnin' For You by Blue Oyster Cult?

That harmony is fairly easy.

I would NEVER recommend this for a beginner,but once you're both used to playing with each other, try the guitar harmony bit after the solo in Trivium's 'A Gunshot To The Head Of Trepidation'

If you get it down,it's easy,fun,and impresses people.
When you saw me sleeping
thought I was dreaming
of you...

I didn't tell you
That the only dream
Is Valium for me
The blues jam idea is a good one. Teach him various shuffles, and licks in different positions. Jam to songs which have a repeating chord progression, and a good melody that you can play with in a solo. Like Autumn Leaves, or No Woman No Cry sped up a bit:

  F       G        C             G         Am