You know who does need salary relief, the Clippers.
How about something like this?
Celtics Receive
#1 (Blake Griffin)
Chris Kaman
Baron Davis
Clippers Receive
#2 (Ricky Rubio)
Ray Allen
Kendrick Perkins
Grizzlies Receive
Rondo
May not be enough for the Grizzlies, but I could see that as a reasonable trade for LAC and Boston. Boston gets a veteran starting PG, a young tough center to replace Perkins, and the PF that could be the base of the next dynasty. L.A. dumps a ton of money, drops back just one spot, picks up a nice young tough and cheap center, and adds a solid veteran to help Gordon, Rubio, etc. come along. If the Grizzlies were going to take Rubio, Rondo makes sense. If Memphis is leaning towards Thabeet than perhaps you send Perkins or Camby to them in addition to Rondo (and maybe Conley out).