Some while ago my wife brought me a Maplin badged, Watson WH1081 weather station. It has an outdoor unit which measures temperature, wind speed and direction, humidity and rain fall. A wireless indoor unit then displays and logs the data. The indoor unit also has a USB port allowing it to be connected to a computer of some description.
The Software that comes with it is fairly basic, however http://sandaysoft.com offers some free and very powerful software call cumulus.
The cumulus software will talk to the indoor unit, manage the data logger, produce charts as you might expect. Then come the great stuff, it has built in tools to upload the data to a web site of your choosing, via FTP, as well as uploading the data to several weather services. A recent addition to the feature set is twitter. Cumulus will now send a tweet on a predefined regular basis with a summary of the current weather conditions
Mine is now tweeting to http://twitter.com/abbeymeadwx