How about using
Gmail that has spacious 10MB attachment limits and some kind of splitting'n'splicing software... or host the files on anybody's webspace they get free with their domestic ISP... or sign-up with a (free) website making site (e.g.
Angelfire) and host it there with some encryption on the file itself (1GB bandwidth's not unheard of), or use some P2P application to share it with a dripfeed download over a few hours... or put it on a media card & post it?
Any goers?
[edit: or without even emailing the files, upload them on the Gmail account and give the sub-contractor the address and password and let them download direct from this utility/communal account

]