you can see from that great map that Piglet gave you the link to, that there are several close. The closest being Best Western Park Place Inn and the Park Vue Inn. That being said, most people consider from Howard Johnson's to the North, to Candy Cane Inn to the south to be a fairly easy walk. I recently stayed at HoJo's and found it to be a very easy 10 minute walk. Some people are comfortable walking from farther out hotels, it just depends on the walker, I guess.
I'm not sure if you have been there before, but you can only walk into the pedestrian walkway on Harbor Blvd, so right at that red square on the map, or some people who stay on Katella talk about cutting through the Grand Californian to enter through Downtown Disney. I have never done that, so I can't really comment on that.