Well 25MB is on the large side (although some recently have been up there) but I usually deal with files in the 2-10mb range, which has been fine in the past.
I've heard about these filesharing systems, but the work I do involves (usually) collaboration between people from many different companies, on a project lasting a few days to a few months, then all change.... so anything that requires us all to have the same system is well nigh impossible.
PS ... still waiting for Thunderbird to finish importing....