I don't know where Nash could go ... there aren't many possibilities unless he forces his way out of there.
Playoff Teams
East -- BOS, MIA, ORL, CHI, ATL, MIL, NYK and maybe IND
West -- LAL, DAL, SAS, OKC, DEN, UTA, NOH and probably PHO
You can rule out several teams that are already locked and loaded at the point guard spot either with a superior talent, comparable talent or younger talent who's development they do not want to interrupt. As well as Phoenix themselves.
East -- BOS, MIA, ORL, CHI, ATL, MIL, NYK and maybe IND
West -- LAL, DAL, SAS, OKC, DEN, UTA, NOH and probably PHO
I have a tough time seeing Dallas make a run at Nash. They already have Jason Kidd there and Phoenix won't have much interest in most of Dallas' squad. Nash doesn't fit into the Triangle offense so I'd rule out LA too. Plus, Miami has nothing to offer up in exchange for him outside their Big Three which they are not parting with.
Atlanta likely wouldn't part with JJ, Horford or J.Smith and they don't have enough to offer up for Nash otherwise so I'll rule them out too. Ditto for Indiana due to a lack of trade assets. Denver would be very interesting but I can't see any trade package that they could offer up for Nash. Billups is too old.
East -- BOS, MIA, ORL, CHI, ATL, MIL, NYK and maybe IND
West -- LAL, DAL, SAS, OKC, DEN, UTA, NOH and probably PHO
Orlando is by far the best home for Steve Nash. They need his creativity and they could offer up Jameer Nelson as a replacement which is likely the best trade package anyone can, or will, offer for Steve Nash.
The other option is the Knicks and building Phoenix East. Not a title contender but a good team. This could become a much more intriguing option if they added Carmelo Anthony first. Trade one of Gallo/W.Chandler to Denver for Melo and the other to Phoenix for Nash. Plug in Azubuike as the starting two. Either Turiaf or A.Randolph as the other big. That could be very interesting.
Actually, another option ... Memphis ... likely sitting outside the playoff picture but they could give up OJ Mayo for Steve Nash. Maybe include Mike Conley and bring back a quality two guard like Mickael Pietrus. That would give Memphis a legitimate playoff team. It's a pretty big stretch though.
Orlando and New York are the only two realistic options for me.