Seattle is poised to join the ranks of San Francisco and Ireland by imposing restrictions on the use of disposable shopping bags. The City Council vote on the proposal—expected to pass by a wide margin—will occur this summer and would take effect at the start of 2009. While Ireland and San Francisco have banned plastic bags outright, Seattle's proposal will instead impose a twenty-cent fee on every paper or plastic bag used by consumers at the point of sale. (The proposal also bans styrofoam food containers.)

What will San Francisco look like 100 years from now? According to the winning entry in a "city of the future" contest, residents will live in a forest of sinuous towers.

IwamotoScott Architecture took home the $10,000 prize for its "Hydro-Net" design, which also envisions an underground web of carbon-nanotube-walled tunnels where people travel in hydrogen-fueled hover-cars.

A: Tagging is the act of assigning your own keywords to things online-photos, blog entries, bookmarks-so that you can easily categorize, locate, and share them in the future. One of the best examples is del.icio.us, which lets you save Web bookmarks to a page on the site instead of to a file stashed away on your computer. This way, you can access them from anywhere and let other people see what sites you like.