First of all, get a long line for you pup. A 11 wk old pup in the classes before mine sadly was hit by a car and killed last week. Sorry to sound a bossy cow! It will also keep him out of trouble with older dogs that don't want to play, as he probably won't have learnt manners yet.
Find out what makes your dog 'tick'. For mine, its his special tuggy toy. I keep it hidden away at home so the only time my boy gets to play is when we are out and about. You need to remember that a proper solid recall is when a dog comes straight away, even if he'd much rather be doing something else!
Practice loads. So, call pup when he's in the garden. Praise like mad when he comes, offer a treat or toy and game. Up the distractions slowly. So, then try and call pup away from his food bowl, or from another family member fussing him. If he doesn't come, go and get him. Don't let him learn to ignore your command.
At the moment, playing with other dogs/sniffing arses/chewing grass is waaayyy more interesting than you, sorry. 
Make yourself an exciting person to be around. I'm sure (Minimuu?) one of the excellent posters on here once mentioned a 'magic circle', meaning that whenever her dog is near her, he gets a treat/game/cuddle or whatever floats his boat. Dog then learns that around you is a brilliant place to be!
My boy is nearly one, and has a really good recall. Not perfect, mind! 
If we are somewhere new or not a safe area, I take my long line with me.
I do lots with him on walks though, calling him over frequently, playing tug or chase with him, throwing his ball or chucking him bits of sausages!