OK here's the scenario:
I have 2 different computers, a laptop and a desktop. I have a file on my laptop that I want to transfer over to my desktop, but it's too big for e-mail or flash drives. The 2 computers are connected through my wireless router.

So, can anyone help me understand how to transfer about a 10gb file from one to the other?

Thanks in advance.

I have no idea. I have a portable hard drive for instances like this.

That might be the route I take. Too many songs and movies.

Flash drive

Share out a folder on the target machine. On the source machine, simply save the file (or copy it) to the share on the target machine.

http://www.laplink.com/pcmover

Buy this software.

Instances like these are why I got a 16G flash drive.

Is it one big file, or is it a folder, the contents of which can be split up for transfer?

I'm glad my brother got me an external hard drive. I can just keep everything there for instances like this.

I've just can't risk another computer crash and all my stuff being on it's hard drive.

they are USB transfer cables out there. i think the one i have is Belkin or something. i transfered most of my desktop over to my laptop in no time at all.

I moved my whole music library from my laptop to my desktop. Placing everything in the shared file works great.

Yes, just share the folder on the laptop.