So here's a little tidbit. When you're using Compass with Rails, check to see if it slowed down your tests. I used test_benchmark, and saw that it increased my test times 3 fold. I narrowed it down to the initializer/compass.rb files that gets loaded. Tests should need to use Compass at all to make it work, and just wrap its contents, like so:
if RAILS_ENV != "test"
# If you have any compass plugins, require them here.
Compass.configuration.parse(File.join(RAILS_ROOT, "config", "compass.config"))
Compass.configuration.environment = RAILS_ENV.to_sym
And that'll do it.
I got too lazy to put this in a gist. It'd be really nice if posterous let you edit gists in-place in their editor.