Any good vpn solution will do that.
I've had experience with:
Microsoft ISA server
Cisco VPN Concentrator
CheckPoint
They all performed flawlessly, but I found the MS ISA server solution to be the easiest client setup. If you're using a PPTP connection, talking a user through it over the phone is cake.
It is also easier to configure the server to use a MS domain authentication. The other enterprise-class vpn solutions can do this, it is just not as seemless.
Don't get me wrong, any good vpn solution will work, but many of them require deployment and configuration of proprietary software to the users.
Anyway, that's my $.02
MCSE CCNA CCDA