Where have you found the best supplies? cheap or interesting

Sea glass is sea glass, I'm guessing...so where have you found the best prices and selection of mosaic supplies? Online or local? Is there somewhere that offers free shipping? That would be excellent since this stuff isn't lightweight.

I'm still thinking on that backsplash project, and wondering where else I can look for those 'interesting' pieces to add to a project rather than just going with tiles.

Thoughts? Going off to search, since I didn't do that before posting THIS, either. ;)