I'm going to make a side trip to Prague, while I'm in Germany for World Cup, is Prague still a good deal? What are the things I must see and do?
Go to Krakow instead. Or Budapest. If you go to Prague go to and see the Astromical clock in the town hall square - but avoid eating or drinking anywhere near there like the plague. Staropramen brewery is a fun couple of hours. http://iglo.lundegaard.cz/staropramen_new/centrum/eng/index.html
Prague will be very busy during the summer. If you are going, try to book ahead a few months. Learn a little Czech as the people will appreciate it... even if it is just mluvite anglicky (do you understand English). Someone mentioned the food in and around Stare Mesto.... it is much more expensive then what you would pay outside of Prague and even outside of the city centre. Oh yeah, I wouldn't say Prauge is a good deal, but I suppose that is all relative as to how much you have to spend. I haven't been to Prague since 2002, and I usually only use it as a base to get into the Czech Republic (by plane) so I'm not that much help. I'm going back to the Czech Republic this March and I'll be flying into Brno.... I can't wait!
From what I have heard Budapest is more interesting than Prague...unless you like "Disney & McWorld" type places. However, I know people who have really enjoyed Brno....which is where some of the better Pilsner brewers reside.
I live in Prague so I can probably help; for starters most of Prague is still cheap by more western standards if thats what you are wondering about. However there are areas where you can spend alot of money here as well, in general the further from Charles Bridge/Old Town you get the cheaper. For sights old town and the castle are where you will find the highest concentration of historic landmarks. If you have any particular interests or want to know good restaurants or bars I can try and help.
Prague is more popular with tourists than Budapest, and this really annoys the tourists who like to think themselves a step or two ahead of the common herd and enjoy dismissing anywhere that's popular. I like Budapest, but while it may feel a bit more "authentically east european" than Prague, Prague outshines it in almost every other respect.