OK, so I signed up for I2K's DSL service around Christmas 2003, and I love it.  I hope I never have to see dial-up again.  But here's a weird thing some network-savvy guru might be able to explain: 

The IP address I2K assigned me (the public one) is 192.168.XXX.XXX (no, not with the X's).  I can resolve web sites on my box using that IP from inside my LAN at home, but I can't get them from work (or seemingly anywhere in the wild).  I found some documentation that explained that 192.XXX addresses don't route, which explains that issue.  I confirmed that with I2K and other sources. 

The kicker is that my parents, who live 40 miles away (and thus are not on my LAN) can resolve sites on my machine.  The only explanation I can think of is that they use the same ISP (though they use a dial-up account), and somehow my address routes ok inside I2K's internal network.