[lch]

I'd suggest increasing the file size limits a little. How does this sound:

jpg, gif: 250 KB
other image formats: 500 KB
doc, txt, xls, pdf: 500 KB

Maybe even up to 2 MB for PDFs. If somebody writes a manual, people should be able to download it without the need to unpack it first. I don't suppose people are going to be attaching a lot of big PDFs without any reason.