As a security conscious person, I like to keep all aspects of my home network private. This includes leaving ports open on my router, which is mostly a no-no in the enterprise world.
Sophisticated brute-force logins programs can easily crack an Apache passwd file if your Apache settings aren't enforced correctly and your password is easily guessed. I'm sure there's documentation about this all over the net, just google: "Apache Security Tips". Keeping in mind, some tips mentioned might break Apache - so backup your configs if you decide to muck around.
On to the private network tunnel. I'm an IT Systems Engineer for many clients and I'm constantly on the move. I have been using Hamachi for quite some time now to keep connected to my home network while I'm on the road. While this isn't the MOST secure or direct route, it works as a temporary solution opposed to VPN (PPTP).
I just wanted to shine some light on internet security and vulnerability of having Apache wide open to the public internet.
Visit the Hamachi site, learn it, and become a little more secure.