http://shop.lessenteurs.com/ is the only one I'm aware of, sadly. Otherwise, there's a few very good sellers on eBay, like kaoslink.
I ordered from The Perfumed Court recently, and while the samples were a pretty good price and hard to find, they too took about a month to arrive. It's something we're sorely missing in the UK.
EDIT: Here's a good thread for reference: http://www.basenotes.net/threads/269...d-samples-(UK)