I don't really have the money, but I bit the bullet and bought a Permanent Account. I did it primarily because I already have so much writing on LJ that I didn't want to disappear due to inactivity or unforeseen circumstances.
I partly justified it by pro-rating the 3/12 years I've been on LJ: Certainly the time spent already works out to just pennies an hour. It's already been cheaper than my domain host. While I have no faith in the permanence of the parent company, it's likely to be around for a long time, and now LJ is my third commercial host.
If I can figure out how to do it, I'll probably change how I post pictures. Ideally, the switch will be transparent to readers, but I'll post the pics on LJ rather than on my site. I won't get the cool stats (LJ Friends are a huge proportion of my hits due to the pictures) but I'll save on bandwidth. And possibly, they'll load faster, which means I can increase the resolution. We'll see.
Okay now: I've never had a paid LJ account before. What cool features should I experiment with?