icQ can work, basically you just have to do a search. People who are online will show up and you can chat with them. Once I met an Estonian girl who wanted to maet in a neutral city (she offered to pay airfare) which turned out to be prague at that point in time. I didn't follow up for many reasons.
The guy who said try a known site like meetic, etc is completely off base. Those sites are known in the west, but in the east it is a completely different ball game. For example, one of the only countris where google is not an internet search leader is Czech Republic, where seznam.cz is the leader.
Seznamka.cz is a great source for meeting girls, but now that they have hidden the english language section (3 years ago it was on the front page menu, but not it is buried several clicks deep) it has less traffic. But you can get still get great results on there. Any kind of czech girl you can imagine goes on there when they are looking for a man. If you go in the czech section, there are many girls asking for a man to sponsor them (that means give them rent money in exchange for dating). I've heard of girls meeting foreign girls on there and moving to there country to marry them. I know one!
Globally, economic prosperity is not the only origin of the desire to meet/marry a foreign man. You can find such girls in every country, so they will gravitate to the websites where they can meet foreign men. IN the case of Czech Republic there are a lot of girls who want to live the high life and the average 1000EUR/month salary in prague doesn't cut it for them. When I first moved to prague my first girlfriend told me that to live well the man needed to make 10,000EUR/month. So there is that factor. But the Czechs are jaded after almost 20 years of poon hounds going there trying to get laid.
Girls in Slovakia and Poland are much more crazy about the prospect of a western man. And for those in the know, they also have a reputation of being better looking.
Other sites that deliver good results are rande.cz and libemseti.Cz. These are 100% czech so very difficult to navigate. But libemseti seems to be the site that the young people favor. But some girls are on there just to get a free meal or a free invitation to a movie. While it might seem cheap to you, on their 500EUR / month budget it's a big thing (the average salary in CZ is much less than the average salary in Prague, which is something like comparing the average salary in New York to the average salary in USA).
For those dating websites where you have to pay a big fee. I think it is a waste of money unless you need hand holding. One girl i went out with when i was living In prague, very beautiful, told me after we broke up that she had to go on there to find an American guy, because the kind she wanted didn't want her. She was more than a little big psycho! And in the end she didn't fidn any boyfriend or husband of there. One of my friends saw her on one of her dates and he said he looked very happy and she looked very sad!