Has anyone used or know of a GPS unit you can use on foot to sitesee? I don't want to use my phone and I was hoping there is a handheld unit out there.
There are many models of GPS that are made for hikers but I wouldn't get one for walking tours. GPS needs a clear "view" of the sky and walking in cities with tall buildings and winding streets they lose a lot of accuracy. You also need to walk for a block or two for a GPS to know your direction of travel and you'll waste a lot of energy walking back and forth. If you are going to get a GPS I recomend a car unit that will double as a walking unit.
The most useful item I have found for walking around cities is a small compass and a map.
Assuming you mean urban sightseeing Richard's suggestion of map and compass is good advice. A GPS and maps would be appropriate if you are in the bush (countryside) where signage isn't dependable.
I use the Wifi GPS function of my Ipod touch when sigh seeing in urban environments. Works great for me. Paper map and compass is soooo 20th century LOL. Here's a previous posting I made on how to set it up:
I've been using a Garmin Nüvi GPS for walking tours for many years, and it's worked reasonably well. Although it's primarily designed as an automotive model, it also has a "pedestrian mode", which is what I use when walking about. I've found that it's necessary to have a clear view of the sky when getting an initial fix, but after that it seems to work reasonably well, even among tall buildings. The one weak point of using the GPS for walking is that battery life is not all that good. I often just switch it on and get directions, and then switch it off again.
I found that I was using my iPhone and Google Maps a lot more on my most recent trip, rather than the dedicated GPS unit. Once the starting point and destination were plotted using Wi-Fi or cellular data, I could switch the data "off" and just use the GPS functions of the phone. I have to do a bit more experimenting with that, but it seemed to work fine.
Sorry, I'm not informed on GPS options. In European cities, paper maps are usually free at your hotel or the Tourist Office and subway/bus stops and touristy street corners often provide useful signage. Recently, I visited a few smaller towns without a map or guidebook in hand, relying on the tourist direction signs that happened to be on every street corner (for instance in Urbino, Perugia, and Volterra).