You could make it a little game to pull him up to a sitting position - start with him lying on your lap, have him grab your fingers (or you grab his hand) and pull him up while talking, singing or making silly noises to keep him entertained. Let him balance for as long as he can, and then help him plop back down (again, making it a "fun" part of the game). When he gets the hang of sitting a little, I would sit him down between your legs, put an interesting toy in front of him, and help him balance while he plays.
The boppy pillow was great too - it helped provide a soft frame for him to wobble within (of course you still need to be there for the big falls).
at 10:43 PM on Apr. 22, 2010