SSL VPN
Does "Apple's VPN" support "SSL VPN"?
MacBook Pro (Intel), Mac OS X (10.6.1)
SSL VPN (i.e. something like the SonicWall/Aventail appliance) provides its own client (usually Java-based) and should work fine. Most SSL VPNs can provide the client directly in a browser, or allow the user to download a client app that they can run without the browser.
There is a DNS bug in 10.6.x currently that causes DNS resolution issues with any kind of VPN. After connecting, 10.6.x usually won't resolve internal DNS names from the VPN'd network: it continues to run them all through the local DNS and never checks the VPN's DNS servers. In order to get VPN'd names to resolve properly, you have to do a killall on mdnsresponder, which makes it resolve properly. You have to do it every time that you connect to the VPN, though.
There is a DNS bug in 10.6.x currently that causes DNS resolution issues with any kind of VPN. After connecting, 10.6.x usually won't resolve internal DNS names from the VPN'd network: it continues to run them all through the local DNS and never checks the VPN's DNS servers. In order to get VPN'd names to resolve properly, you have to do a killall on mdnsresponder, which makes it resolve properly. You have to do it every time that you connect to the VPN, though.