Bulldog, I had the same question while I was shopping. What I found is that some lenders will allow you to do a "preliminary application" that will allow them to run your credit report and get your salary info, etc. in order for them to give you a Prelim GFE. For example, I talked with a lender from First Horizon and he was able to give me a "preliminary GFE" based on the info I'd furnished. Same deal with a local Credit Union mortgage lender that I spoke with.
The key is to make sure -- up front -- that you fully understand at what point you're "on the hook" for an application fee. My experience was that the moment you tell the loan officer / mortgage consultant that you want to lock the rate, you have at the point made a commitment to them. At that point, most of the lenders I talked with said that there would be a fee of about $350-500 to cover the appraisal.
General tip: if you call a lender and you are getting confused about when fees apply and when they don't, ask them to clarify right then and there. If the ensuing clarification only adds to the confusion, probably time to call another lender.