I haven’t come across anything other than the obvious [and crap] herbal ecstasy tablets sold at on-line “hippy shops” and the like.
There were on-line drug dealers (including an SSL site which delivered weed throughout the UK!) but the post 9/11 Internet ia now one of the most highly monitored and soon to be regulated forms of communication; there has been a considerable effort in most Western countries to flush out and shut down sites selling any kind of drug over the net.
Many of the remaining companies are unfortunately now rip-off merchants or based in countries where in the current world climate any shipment of anything would be monitored. That includes the “new european” countries in Eastern Europe…
Ordering naughty stuff over the internet leaves a breadcrumb trail of data which can be (and is) followed by law enforcement. Posting a site on here would guarantee cops see it from British bobbies to the FBI and a few European forces as well…
You might be able to score some mild stimulants or tranquillisers which are “legit” pharmaceuticals and less restricted in some countries; but you may also end up paying your money and merely getting a letter from your countrys Customs authorities that the package has been confiscated 
As always the best way to make a connection is to meet like ninded people from raves. The Internet is good for a lot of things, but buying potentially illicit substances (although it happened) is no longer a safe thing.
