I'm intending to spend 6 months in Stuttgart in Germany starting from June 2014, and I'm searching for student dorms to stay in for one month until I find a room in a shared apartment. I'm willing to pay up to 400 Euros per month. I've tried to ask in Kolpinghaus in Stuttgart, but they don't have any free rooms left.
Studentenwerk Stuttgart is the public provider for student dorms in Stuttgart.
As their website states (sorry, only german), short term rental is possible, but has to be checked with each facility. Use the email addresses provided in my link, the dorm offices are usually run by students, so an English request should be just fine.
Please note, most dorms are located in Stuttgart-Vaihingen (south-west of Stuttgart), S-Bahn stop is "Universität". There's only one for short term listed in the city center (Max Kade Haus).
I used to live in "Straußäcker I", which I really liked, but that was 8 years ago :-)
There's also a list of other dorms, which may offer short-term rental.
The dormitories operated by the Studentenwerk Stuttgart give priority to students of the local universities:
This means, your chances are pretty bad.
However, they also operate an "international student hotel" which seems to be exactly right for your requirements. It has shared apartment style rooms for 310 to 330 EUR per month.
The University's website on temporary accomodation lists a number of hostels as a (probably pricier) alternative.