Using Nuvi in Venice (and other places with non-standard addresses)

Hi
I just got back from my first use of the 370 walking in Europe, in particular, Venice. We had no internet, so I could not go into google maps and then download coordinates to the nuvi.

So mostly ended up just looking at the map and seeing when we got near Grand Canal or other places I knew about (or some points like our apt. marked before I left home).

But when I tried to enter addresses, I just frequently failed. Thus, for example, I was frequently looking for restaurants (not in poi's, but not expected or wanted to be) in various campo's (eg. campo san polo). I tried just putting in campo and even c, but never found this campo.

Since i mostly got the nuvi for walking in european cities, is there a good trick for entering addresses into the nuvi, similar to the discussion of rural roads in the us of a few weeks ago.

I note that my apt was dosorduro (one of the six districts in venice) 3xxx. Nuvi did not understand this system. Google gave me the coordinates immediately which i could then download via takitwithme. but with no wireless, this failed (though the upside of no wireless was a real vacation!).

So any helpful hints from nuvi users in Europe. Or is simply watching my movement on the map the best I will be able to do. (Venice is particularly hard since the narrow streets allow for only a very narrow vies of the sky, and being 30 feet off can put you either in a canal or on a parallel street, so woodenheadedly following the nuvi instructions could lead to a very wet journey!).

tia
neal