Aviation weather
My best recommendation is to use Metcheck
http://www.metcheck.com/V40/UK/HOBBIES/aviation.asp
Skylink is another good aviation weather site with free aviation forecasts, Taf's Metars, etc.
http://skylinkweather.com/metar/metarmapindex.php
The Met office also provide aviation weather, which you will need to register for
http://www.metoffice.gov.uk/aviation/ga
Wendy Windblows provides an amazing service. Live weather data from hill top weather stations, in my opinion this is the best service for hill flying on hang gliders and paragliders.
http://www.wendywindblows.com/
ActivityGifts.co.uk