Travel Advice: Southeast Europe edition

Hey'oh there Duders!

The premise here is pretty simple. I'm going on a short Interrail trip to Southeast Europe next month. My current planned route would be Prague-Bratislava-Budapest-Belgrade-Sofia-Istanbul, but I'm still open to some slight route changes. I was just wondering if there are any locals, or seasoned visitors to these places on the forums who would like to help me out in my travel planning. Any advice is welcome, from local customs to places to drink or eat at or how to best get around. I'll likely be spending only a couple of days in each city, and I'm trying to keep to a reasonable budget but any hints are welcome.

Also, I was pondering if it would be smart to create one united "Travel Advice" thread on the forums since threads like this seem to be popping up from time to time? Then again separate threads are likely to create more focused answers for the duder in need of them.

Prague is our local mini-Vegas (about 300km from where I live). Basically, great place to party. check out the Roxy club (used to be an opera or something) or the multi-story Karlowy Lazne.

Haven't been to Istanbul yet but I've seen a documentary about the flooded underground tunnels - cisterns (?). That would be something I would love to see.

Have a great trip!

@locorocker: Yeah I've read about Karlowy Lazne. I usually don't go out clubbing when I'm traveling, but might make an exception to check it out.

Moved to Off Topic, General is for games and stuff about the site.