The German Linux Magazine runs a sponsored "Open Source Project Lounge" at CeBIT each year. Last year I put in a proposal for +DAViCal and it got accepted! With some airfare support from InternetNZ I got to showcase my Free Software project at the largest IT trade fair in the world.
If you have an open source project to promote I can't recommend this highly enough.
I go to lots of conferences where I see many worthwhile free software projects, but in general the people showing off there are "preaching to the choir". We all know them and love them. At CeBIT you're presenting your project in a wider context, and you'll have a few hundred thousand people walk past your booth, see your logo and stop, listen and learn. I don't speak Deutsch, but that's no handicap - there are people from all over Europe going past, and many of them speak perfect English. There will also be people on the booths around you, or a keen volunteer or two from your project who are already in Germany will happily volunteer to help out (they get a free day at CeBIT out of it).
Free Software typically doesn't have the budget to present at events like this - even a tiny booth of 6 square metres or so cost upwards of €10k when you take all of the costs into account.
If you do apply, and you get accepted, I'll happily offer more advice too, but that's a different story. Seeing this has prompted me to write up my experience on my blog too, see http://v.gd/cebit_2011 for more details of my trip.
Good luck!