The fact that he has Dial-Up and no other resources presents a new twist to the problem. Maybe he should be more specific as to what he wants to do. It would appear the OP wants to share files with his friends, but the flies are much to large for him to host or even FTP. (FTP is a protocol for sending files.)
The OP also mentions that the files may not always be available, or they could be deleted.
If he has friends with resources, they can help him with his project. Assume he has a worthy project. Maybe he is collecting public domain documents about government oppression and these documents disappear after awhile.
There is a way to pass a list of URLs to a friends computer and his computer will immediacy try to FTP the files and schedule a retry.
This falls into the broad topic of P2P. On this forum P2P is not a polite thing to talk about, because it is often used to circumvent legal restrictions on content.
Nevertheless, there a re worthy projects were a group of people work together on a project and gather information for study and research. If he has friends with high bandwidth, he can use their computers to copy and store files. Network administrators do this. They can control remote systems over a office or home computer located far away from the servers. They is a form of remote administration.
http://en.wikipedia.org/wiki/Remote_administration