I can only recommend the devices I've had direct experience with. These are the good ones so far:

Freedom 2000 GPS on an HTC Wing with Microsoft Pocket Streets and Google Mobile Maps

Pharos GPS-500 with Microsoft Streets & Trips* on a Compaq Presario V2000

HTC G1 with Google Mobile Maps (fine, but not yet tested in Europe)

I eliminated the dedicated units right off the bat because a) I don't want to carry around more pieces than necessary, and b) using components means I can upgrade software and hardware independently.

* You can try out the 2009 version here: http://www.microsoft.com/downloads/d...DisplayLang=en

"I can hardly imagine getting lost in Venice."

I did once. I managed to wander into a residential area and couldn't find which way was out. I can get lost anywhere, even retracing my footsteps around the corner.

Can't imagine a greater contrast for testing a GPS than walking the lanes of Venice and the open spaces of Australia on a driving trip.

<i>Author: Remus
Date: 12/13/2008, 12:00 pm

[Judith Martin] will bring you to places that no GPS can!</i>

I hope that travel guide writers and services web sites will begin soon to publish lat/lon as part of the sight or property description. Street addresses are subject to all manner of vagary, but there's only one spot on the earth with a particular co-ordinate pair.

Then travelers could build up a set of personalized points of interest that would eliminate a lot of plotting and routing (and, in the case of the Abbey at Fontevraud, a lot of unnecessary marching).