How To See My IIS From Outside?

I use my IIS intallation to check websites I've developed on my own machine via the 'localhost' URL. Works fine. But recently I was asked to make my machine available to the world so's a friend (my brother) could do a file transfer.

I googled and found something that said if he input my IP as an URL he'd get it.

But it didn't work.

I have a permanent IP. I run WinXP SP3. There's a small home LAN behind a BIPAC 1500 broadband modem/router.

I checked IIS in control panel and found nothing to help me. It is apparently listening on port 20 - that's usual for HTTP, isn't it?

Can anyone help?

HTTP is port 80
To get to your web server from "outside" all these things need to be correct
- Your Internet provider must not block port 80
- Your IIS server computer has a fixed LAN (internal) IP
- You need a valid DNS name for your location or the user needs to know your external IP
- Your router must be configured to forward HTTP to your IIS server internal IP
- Your IIS server firewall must allow HTTP through