Want to be among the first to know when a new non-native aquatic species shows up on your doorstep? If so, go register at the NAS Alert System. This "Nuisance Aquatic Species" early warning system, sponsored by the federal government, will send you an email every time a new non-indigenous species is found in the state(s) of your choice. You can also tailor your alerts to be organism-specific, or choose from several of the "invasive species-du-jour" listed at the bottom of the page. The site still has a few kinks to work out (MSIE-specific, no contact info on site, and it's "ruffe" guys, not "ruffie"), but a great service like this is long overdue. I subscribed to all the alerts, of course, and will be sure to feature some of them here at the ISW.
Update: Wow - that was fast! Got my first alert...A Northern snakehead (Channa argus) has been found in a lake in Pennsylvania! Read the alert here, the press release from the Pennsylvania Fish & Boat Commission here, and see the updated USGS map.