I was wondering if anyone has any suggestions for somewhere to go in Europe for a 6 day vacation (that needs to be relatively cheap...ie. probably hostels, etc.). I've been to the UK and Paris, but nowhere else. Since I only have 6 days, was thinking about going only to one country (? maybe Belgium).

I'd appreciate some thoughts...

The northern countries are not necessarily cheap. I'd investigate Portugal.

Depends on what you consider cheap. Have you looked into flights+hotels at places like expedia or gotoday? You might find something there. If you want to save money spend all your time in just one city.

What time of year? When you go affects the cost (some places more than others).

Where are you flying from? That obviously affects your flight costs as well as how much time will be eaten up from your six days. Also, it may give ideas for which airports are cheaper to fly into (for example, Chicago>Frankfurt and Chicago>London are usually cheaper - due to carriers, demand, etc. - than, say Chicago>Rome or Chicago>Budapest).

What types of things do you like to see and do in Europe? Budapest with day trips would be great, but Croatia would be fun for sun and sea. Personally, I found Bruges and Brussels can be really enjoyed for not a huge amount of money. It all depends on what you're interested in.

Also, as you most likely realize, the more you move around (not that you would want to in such a short amount of time), the more it costs in transportation, etc.

If you can't find a package trip that makes you happy, consider flying into Paris and then heading down to one of the provincial cities... Dijon, Angers, Bourges, Montpellier, etc. They offer plenty to interest someone for six days and hotels and restaurants will be much cheaper than in the capital (for example, in Angers, you could get a perfectly nice hotel room for $60 a night and eat a good three-course lunch with wine and coffee for $15). You'll get a lot more for your money.
Graz or Salzburg, both in Austria, are interesting cities in beautiful settings. If you fly into Brussels, you can catch a cheap flight to Graz or Salzburg on a budget airline (we're flying to Salzburg from Charleroi, Belgium, for about $20 per person).

Thanks everyone...

To answer a few questions above, I would be going either the first or third week of July (I know...high season, but I don't have a choice). I'll probably fly out of either Chicago or Detroit.

I had initially thought about staying in one city, and then doing day trips, which is why Belgium came to mind...

Belgium has got a great train system, and easy access into other countries. I'd pick Antwerp as your base, although there may be other cheaper options, like Ghent.