Is 3 teams really all that much in the modern era or in a 15+ year career for that matter? The salary cap seems to have somehow reduced this a bit (less room for contenders to stockpile stars), but in the 80s through 90s there was a lot of big name trading going on. It seems like almost every star of that time played on 3 teams at least in their career.
I wouldn't think of Chelios as a nomad for example. Chelios spent 7 years on the Habs, 9 years in Chicago and 10 years in Detroit. He became part of the 'inventory' at all of those stops.
Mark Recchi would be the first one to come to my mind as an actual nomad, simply because he was one of those guys who was an All-Star level scorer but no-one ever seemed to view him as a franchise player. Dude played on 7 teams, including two stints each with Philly and Pittsburgh, and managed to put on two different uniforms in the same season on six separate occasions. His longest stint was 5 years and some change with Philly.
Ray Whitney wasn't as good as some of the others mentioned here, but I also remember him as a solid scoring journeyman who'd stay a couple years and then go to another team. I mean heck he scored 10+ goals with San Jose, Florida, Columbus, Detroit, Carolina, Phoenix and Dallas. Definitely a guy who would have been well advised to rent, not buy, in the cities he played in..though I guess depending on the real estate climate you may make some money buying and selling every 2-3 years.