What's the seasoning? I'd think that might limit it's use?

I've actually been successful using it for burgers - season and top with Asian flavors. I get a little water on my hands, form the patty and then put it in the refrigerator for at least 30 mins before plopping on the grill or pan. As gaobest said, they also make great dumplings. Mix with veggies and spices and wrap in some wonton sheets and bake. Also, look up recipes for white chicken chili, which uses ground chicken.

As for the other meats, ground pork can be used in much the same way as the chicken. Same for turkey, although we use it a lot in red pasta sauces too. Ground lamb makes great burgers, or shepherd's pie. For lamb burgers, look for a Mediterranean recipe -- think cumin, feta, red onion, etc. My wife doesn't like lamb, so a homemade lamb burger is a rare treat for me.