Lindau is nice, very pretty little town. Friedrichshafen might be worth a look too, the Zeppelin and Dornier Museums are both excellent. Ravensburg I haven't been to but it's supposed to have a nice Medieval centre. Ulm has Europe's tallest cathedral, the very pretty fisherman's quarter and solar powered ferries. For all that, I didn't find it a very likeable place and I know a couple of other FTers who felt the same.

The Tirol would definitely be a good place to go. Innsbruck has excellent transport connections, a very nice old town, and masses of nature close by. Some of the railways to and around Innsbruck are spectacular, the railway to Seefeld is great and the ride to Feldkirch is lovely too (the Brenner pass is supposed to be superb, i'm hopefully taking that in this year). The Stubaitalbahn will probably change the way you look at trams forever. You might want to consider the Achensee which is a mountain surrounded lake with ferries and a narrow gauge steam railway. Hall in Tirol is another town with an attractive old centre.