Validate upload size before starting upload with Filefield? I'm doing some pretty massive uploads, up to 1gig. Right now if I upload a 1.1 gig file it uploads to the limit then fails.

Is there any way to make it fail before even beginning the upload?
The only easy way to check a file upload's size on the client-side that I know of is with Flash.

You should see if the Uploadify module  works for you. I haven't used the module, but I have used Uploadify a lot, and it works great.