I gave him solids a month early*. He really didn't seem satisfied after the morning nursing, fussing only an hour later. So I fixed him some rice cereal with a little thawed you-know-what. And he loved it.
I'm afraid to change his next diaper, though.
*There's a rift in the American Academy of Pediatrics about this - some say 4 months, some say 6. E is almost 5 months old - and wearing 9-month onesies!