I've frequently run into a problem, and I'd like to know how to work around it. As always, this BBS is a gold mine of minds, and I'm sure someone here can help me.

Often, I want to exchange large files with a friend. Only one friend, directly, not share them with the world.

The following options work, but they all have limitations:

- We can email the files. But the limitation is that many people's mail servers have caps on the size of file attachments, either incoming or outgoing, or both. I hit that problem far too often, and splitting the files up into multiple emails is unwieldy.

- We can use the direct-file-transfer feature of instant messaging applications (or heck, IRC DCC for that matter). However, these don't work behind firewalls, and rarely work behind NAT. Often, the person on the other end of the line is behind a firewall/NAT.

- We can run an FTP daemon on our local machines, but those also run into the problem of being behind NAT or behind a firewall.

- We can use some FTP space that's been kindly loaned to us from one or the other's ISP. But these usually have size caps on them, so really big files can't be exchanged that way.

In most cases, the person at the other end of the line can chat with me via one of the IM services (I use Trillian so I can be on all of them), but the direct file transfer feature rarely works.

Ideally, I'd like for the IM clients to have file transfers that just worked behind NAT/Firewalls. But failing that, what other options to I have for file swapping big files? Anyone?