I will be visiting Germany for 2 weeks

and was hoping to bring my
N95 and use it while I'm there. I am aware that my
N95-3 will work in GPRS only while there because the 3G frequency is different. That's ok.
Here's my problem:
I've discovered that my US-based AT&T plan will charge me ridiculous fees for data and web access. They recommend buying a prepaid German SIM card for use while in Germany for the 2 weeks.
I've done some searching and can not seem to find a pre-paid SIM option that allows for a hefty amount of data. I would like to use internet, Google maps (w/nav) etc. which use up a lot of data. Is there a such thing as an "all you can eat data" pre-paid SIM card in Germany?
Thanks to anyone who can help.