While I was in Iceland recently I discovered that none of the coffee shops in my area were offering wiFi access. The catch is that Icelandic ISPs are currently charging substantial fees if you use more than one gigabyte of transatlantic traffic per month. So I set up a firewall/router that throttled all such traffic by 1000ms. The owner (and subscribers, if she wants to add them) VPN over the WLAN to get unthrottled (and secured) access. By using M0n0wall I kept all the configurations on a separate, write-protected RAM disk and run the firewall without a hard drive. The result is a very quiet, secure, inexpensive box which the owner can simply power off / on at the first sign of trouble. Even if it were compromised by a hacker their changes would disappear on reboot, making for a very worry-free solution!