This is easier than it looks:
1) Open "Network Connections"
a) Applications/Other/Network Connections (fallback mode menu)
b) right-click on the network icon in the top panel and click Edit Connections
c) any other way that you are familiar with
2) Click on the "VPN" tab and...
3) ...click "Add"
4) In the "Choose a VPN Connection Type" dialogue, click the drop-down and select "Point-to-Point Tunneling Protocol (PPTP)" [it was the last one on my list]
5) Click the "Create" button
6) In the "Editing VPN connection 1" dialogue:
a) Connection name: put what you want to call this thing (Bill, George, anything but Sue; either Romana or Fred!)
b) Gateway: put the gatway specified by x10VPN (at the time of this writing, it was "server1.x10vpn.com")
c) User name: this should be the user login you gave when you signed up for x10VPN
d) Password: this should be the password you gave....
7) Click the "Advanced" button
under Security and Compression, check "Use Point-to-Point encryption (MPPE)". This will automatically change a few things. Leave them alone. Click the OK button.
9) Click the Save... button. (There is nothing to change/set on the IPv4Settings tab)
10) Click the Close button on the "Network Connections" dialogue.
11) Click on the Network icon in the top panel (this is a left-click, not a right-click)
12) Click on "VPN Connections", and click on the name you gave your VPN connection in step 6a
13) Open a terminal and type "ifconfig". My laptop had 4 entries: em1 (hard-wire), lo (loopback), p4p1 (wireless), ppp0 (the vpn). Its ppp0 (or whatever yours is that resembles it) that you are interested in. The address should match what x10vpn has given you!