I've tried it before, it was interesting albeit very short lived for the price you pay.
Its not illegal here, but I can see either government expanding their criteria of what constitutes an illegal drug on the basis of how annoying it makes you to others.
Salvia is about 30 minutes at the very most of strangeness.
I first heard about this on the local news - until I saw this video though, I had no idea what it actually did. For once, local moral panic about drugs is dead on target. Sheesh. Just smoke some weed kids!