Need game advice

I need some ideas on what kind of games I can play with Missy. We go to the park often, and sometimes when the weather is really nice we go in the middle of the afternoon. The problem is that there usually aren't any other dogs there. Missy loves to chase things, but that's all she likes to do. I try playing ball with her and she'll chase it then run back to me. She has no interest in the ball, just the chase. Then then I have to run and fetch the ball and toss it again. I get kind of tired after awhile. And I also get tired of letting her chase me when there is nothing else to chase. Any ideas one what kind of games I can play with her so she can still run after something but I won't have to run?

Yep. And you can work on training too!!!
This is one of my dog's favorite games. I put them in a sit stay or a down stay and then I walk all the way across the field. When I get to the other end I yell "OK" and they come flying. Repeat repeat repeat!! LOL I also do this going up and down hills, good for conditioning! You can also not go too far away and then run a bit away from her as you say ok, it doesn't have to be fast it just has to look like you're running away and she'll really put on the speed, at least my dogs do.

Here are some dogs I babysit playing that game with me.

Down stay
http://mediaservice.photoisland.com/...7796586636.jpg

OK!
http://mediaservice.photoisland.com/...1112257538.jpg

And some of my dogs (and pug friend) playing.

Sit stay
http://mediaservice.photoisland.com/...4029657396.jpg

OK! (Emily ran right out of the pic)
http://mediaservice.photoisland.com/...2491516503.jpg

Sortaof a modified version of what Sheltzee said, but you can toss a treat to one sideof you and tell her to getit. AS soon asshe gets to the treat (and the treat doesn't have to be food, it can be a toy etc) call her to come, once she gets there toss something the other direction. Once she gets that call her again...it will keep her running and help with "Come"