Us, Schalke, Malaga and a 4th team to be confirmed
Incase this helps anyone here:
http://www.newcastle-online.org/nufcforum/index.php/topic,95254.msg4982784.html#msg4982784
I did Duisburg - Amsterdam last month by train. Takes about 2 hours. If there are more than 4 of you you can get a group ticket - however that came to like 16 euros single so maybe you've already looked at that. You should go and see a Duisburg game! Highly recommended, I go every year with a load of mates and have a great laugh
http://i.imgur.com/Bt0h8Dp.jpg
I've heard Gelsenkirchen is a shitehole - we stayed in Dortmund at A&O hauptbahnhof - a sort of hostel-cum-hotel for about 20 euros a night (again good for groups). 30 minute train journey to Schalke and you get free match-day travel with any football ticket!
If you can face a 45 minute train ride (flies by with a few beers) I'd highly recommend staying in Dusseldorf. Absolutely cracking night out, Altstadt has the highest concentration of bars/clubs/restaurants in Europe (they say). There is an A&O hostel there too.