This may have been mentioned already elsewhere, but The Witcher game site has an English translation of the Geralt story "Lesser Evil" in pdf form, here is the link to it:
www.thewitcher.com/michau/monk/Lesser_Evil.pdf
I've also found this link to an article about Sapkowski, and at the bottom of the article there are links to an English translation of his short story "The Malady" in two parts. It's not a Geralt the Witcher story, but it is very good.
http://www.polishwriting.net/?s=author&c=sapkowski
I bought the English subtitled edition of the movie "Wiedzmin",
http://www.imdb.com/title/tt0300657/
which was translated to "The Hexer" for English release; apparently it's just cobbled together from episodes of the TV series based on The Witcher books, and it shows. I can't recommend the movie; it's not well edited and it just comes across as a mess. On the other hand, I've watched a few of the episodes of the TV show, which are being fan-translated into English, and they are pretty good for a fantasy TV show. It doesn't seem like they had a huge FX budget, and the computer animated dragon in one episode, while I liked it as a character, just looked... well, really mediocre. Some of the actors are engaging, others fall flat. The actor who plays Geralt looks good in the role, however. It's worth checking out; it's like a lower budget, slightly more cerebral, Polish, "Xena" sort of show. There are also some topless barbarian warrior ladies in at least one episode! Yowza!
I was thinking about buying a Polish edition of one of the Geralt books and trying to translate it in my spare time; I don't speak or read Polish, but I've managed to do 1/2 assed translations of other things with only the internet and a language-to-language dictionary before. I probably don't have time to do that for real, sadly. I hope the game creates enough interest in the English-speaking world that all the books will be officially translated.