www.dietfacts.com is a great site to use when eating out, but honestly, I don't think there really is such a thing as
healthy fast food. Until restaurants start publishing all the ingredients and trade secrets (not just nutrition info) we'll never know just how healthy fast food is.
I remember seeing a news show that mentioned how fast food places spray their salads with sugar water to keep them from browning. This was several years ago, so I'm not sure if this is still the case, but it makes my point that you just don't know what's in the food.
It's hard to completely avoid fast food all together, but I make an effort to make fast food a rare occasion. Just make the best choices you can with the information you have available and try to eat at home more.
Eating healthy at home doesn't have to be pricey. Dried beans, eggs, brown rice, and frozen veggies are all cheap. If you look around, you may find cheap sources of other protein and fresh veggies too. I belong to a CSA and for a monthly fee I get lots of fresh organic veggies for less than what I spent on non-organic veg at the grocery store.