Hi! I just got back from a Gluten-Free trip to India AND Austria, and spent 2 weeks in Austria. It's too bad you have just missed the Christmas market season, because the baked potatoes and roasted chestnuts are a great and very easy gluten-free snack. I would suggest you make your first stop a Reformhaus (health food store)- you can find them at this site:
http://www.reformhaus.de/branche/reformhaeuser.htm What we did was enter various addresses into Google Maps and make a personalized map with all the nearby reformhaus, and then went on a walk with the locations of about four in mind. It was a good thing we mapped multiples, because the first one had gone out of business!
The premade muffins are especially good, and wrapped individually, so are perfect for travel. I liked the apricot jam filled ones, but the chocolate chip ones are also good. Most of the breads, croissants etc. are not individually wrapped and taste best toasted. I liked the pre-crunchy ones toast bits best that were like toasted bits of bread, but some of the crackers were not that great. The aerated looking ones are particularly blah. You can also buy fairly decent rice cakes in local grocery stores- in fact, I didn't go to any reformhaus in Vienna but just stocked up on chocolate coated rice cakes- the strawberry yogurt coated ones were also good.
I have a blog at www.bookofyum.com that you might find helpful in a week or so, haha. Right now I'm just wrapping up some posts on eating Gluten-Free in India, but I will definitely be posting about Gluten-Free in Austria and including reviews of gluten-free food available in reformhaus and reviews of gluten-free menus.

If you have time for restaurants, you might contact the Austrian celiac society (zoeliakie) and ask for their list of restaurants, also available online somewhere. Oh Pot Oh Pot in Vienna CLOSED last month (DOH) but I went to the Greek restaurant they recommended and there was indeed a big gluten-free menu. (although the food was just ok to my taste, it was safe).
Best wishes and have a good flight! Oh, and at my blog I posted some travel tips for dealing with airline meals that might be helpful. Definitely bring some of your own food- just no fresh fruit, produce or meat past customs.
-Sea
QUOTE (Fiddle-Faddle @ Jan 4 2008, 03:07 PM)

Last time I was there was before I was gluten-free; I had schnitzel at practically every meal, it seemed, but obviously that's out of the question this time!
I especially need to find something I can bring with me on the bus ride from Vienna to Budapest, and on the plane from Budapest to Zagreb, as we will be traveling from mid-morning to mid-afternoon (probably LATE afternoon, I know how these things always go).
Thanks!