I'm making a job application form for a website where one of the fields lets you attach a CV. I'm also mobile optimising the site with media queries. Can any mobile devices upload files in this way and so be able to use the form?
Some devices can, you will have to make sure of it though.
The WURFL database does actually have an attribute
xhtml_file_upload that says if they think this device can do file upload via HTML.
If the device comes through Opera Mini or MXit it should work on many more devices as an interface like these two implement native file uploads.