EDN is reporting a very tiny (quarter sized) full WIFI board for about $20:
...
http://www.edn.com/electronics-products/other/4373837/Tiny-low-power-Wi-Fi-module-enables-Internet-of-Things-4373837
Running at 3.3v with low current standby and operating modes,
it may be of interest for mobile robot remote linking, or making
just about anything you can think of (in a house with a WIFI bridge)
fully Internet Enabled.
If anyone plays with this (or similar widgets for Internet-emabling
your favorite device), please be sure to post your results here,
and let us know how well (or badly) it works for you.
Thanks.
- Keith Mc.