It has been a while since you posted but I thought you still may not have your questin answered.  Plus I'm sure there are other moms out there who have this problem.   Here are some things I did to help keep my son entertained.  I could get a good 30 min out using the stroller, but after that it got touchy.

-Bring one of the snacks he loved in a baggie.  For him was coco puffs.

-I would bring his own "water" bottle with him and he would drink at the same time I did.

-Sometimes I would let him bring a car or truck along.  He never dropped it!

-I ALWAYS planned my run so I ended at a playground and promised him if he was good we would stop and play when mommy was done.

-We played speed games.  Every 5 min or so I would ask "are you ready to go fast?"  After the 1st couple times I was going faster if I wanted to or not.

-On days he seemed to be really restless I would let him listed to my mp3 player.  I always keep some fun kid songs in there.

-Sometimes we played a color car game to teach him his colors.  I would ask him if he saw the blue car.

I hope this help some and good luck.