This is a helpful tip I found out (via Google) which turned out to be pretty useful. It's for FileMaker 7 and above, and it will give you the ability to allow a user to select a file and then allow you to store it's path.
So here's how it goes...
1. Create a container field in your table (I'll call it "YourContainerField"). This will store a reference to the file the user selects
2. Create a text field in your table (I'll call it "YourTextField"). This will store the file's path
3. Create a script with the following steps:
Insert File[Reference; YourContainerField] Set Field [YourTextField;GetValue(YourContainerField;2)]
Please note that I'm having some trouble getting that second line to format correctly - so the second and third lines in that code block are all part of the "Set Field" script step. The reference to the file will be stored in the container field, and the text field will contain the actual path to the file. In the layout where I posted this code, I hid the container field (by making it the same color as the layout's background) and didn't allow for entry in Find or Browse mode.