Where can I buy wine from Eastern Europe online? (Moldova, Georgia, Ukraine, etc)?

You dont want to do that,the grounds are still infected by the nuclear disaster in Cherynoble.

If you are in the UK, you can buy from a variety of online sellers. I have used: http://www.red-wine.biz/

In the USA, it is a bit difficult to purchase wine online. Each online seller has to be licensed to ship to specific states. You can try the following, but make sure you check their shipping restrictions:

Romanian wines (about $5/bottle, by the case): http://www.romvinimport.com/en/index.html

Georgian wines: http://www.shoppersvineyard.com/georgianwines/georgian-wines-c444.html

http://www.wine.com is probably my favorite.

You can search for wines at: http://wine-search-engine1-swicki.eurekster.com/muscat/

Here you go: http://www.wineweb.com/wine-search.cfm

Also, please check russian/armenian stores in your area, usually they carry moldovian/ukrainian/georgian wines. I understand it's not exactly what you ask, but if you are live in an area with such stores around, it would be a better idea then buying them on-line.