Apache question....

If you set up Apache as your localhost will the outside world see your server? Reason is, my computer is not running any kind of firewall at the moment, but I am starting to experiment with php, so I set up the server and php and I am worried that a big hole is now open on my computer if I leave Apache running for more than 2 minutes.

Nope, unless you're connected to the web and someone knows your IP. But most of the time, no.

So if someone on the outside world just typed in my IP they'd see the contents of my htdocs folder?

Also, what if someone ran a port sniffer, would they see port 80 active and just enter right in?

Go here and get this firewall. It's free and one of the best...
http://www.sygate.com

I don't think you should worry much. I know Qtone runs a webserver from his DSL line.

Port 80 is on all the time. Its the port that HTTP uses for your web browsing.

Cool, thanks for the link. I have an extra computer as a firewall, but its a bit of a drive to pick it up at the moment. Lol! But I'll get this firewall up for my own sanity.... hehe.