You may have heard about the data.gov web portal - a resource from the Feds designed to increase public access to high value, machine readable datasets. Data.gov increases the ability of the public to easily find, download, and use datasets that are generated and typically held by the Federal Government. Data.gov provides descriptions of the Federal datasets (metadata), information about how to access the datasets, and tools that leverage government datasets.
The site has a noticeable web2.0 flavor with numerous tools designed to help users share and communicate with others, for example, you'll notice the AddThis tool is used, providing a quick way for users to share details of data they find via many social networks and social bookmarking tools. Additionally, links to share via facebook, Twitter, and via email are also provided.
The Geo Tech user will be pleased to see that data can be searched/mined from several locations including a Raw data catalog (access to CSV, XML, KML, and SHP files) with instant access/download, a tool catalog with a wealth of documents, podcasts, widgets, and other useful documents (for example, access the USGS Global Visualization Viewer for Aerial and Satellite Data) ; and the GeoData Catalog with more than 100,000 data products currently held including Census data and products from FEMA, USGS, EPA, NOAA, BLM and many others - you can jump directly to the Data Catalog at http://www.data.gov/catalog/
finally, if you happen to be looking for State data resources there's a handy State data link that will take you to http://www.data.gov/
statedatasites - this area seems to be in development as many State links are not yet active. A reminder, is State data is on your plate you can also see the HUGE State Clearinghouse data catalog at (http://www.gisuser.com/ content/view/16966/)