I just learned the White Stripes' cover of Death Letter by Son House, and it being my first slide song, i've fallen in love with slide guitar. However, I'm at a loss for what to learn next. There's a lot of stuff on the White Stripes' Album 'De Stjil' which are slide-based, but I don't think many of them are in Open G.

What are some good songs to learn in Open G so I don't have to retune between Death Letter and another song?
Isn't some seasick steve in open g?

Well, i think it is when he uses more than three strings.
little bird on de stijl is open g

there's also a few black keys with some open g and slide, can't remember off the top of my head though
Lots of stuff by Allman Brothers Band. If you're looking for lead slide playing, that band is pretty much perfect. Some newer stuff would be ain't no rest for the wicked, top yourself, the solo to I want to be the boy to win your mother's heart. If you're already into learning white stripes stuff, just look up some of their other songs. Jack White loves playing slide and he really doesn't play in much except open g, open a or standard tuning as far as I know.