It will only work on Internet Explorer, and only in the U.S. right now, but if you're looking to extend the same timesaving search convenience of Google's mobile apps to your desktop, the new Google Toolbar (download) from Google Labs will do it.
The My Location feature found in Google Maps for Mobile--and recently integrated into Google Mobile App--uses cell tower triangulation or GPS to find your approximate or exact location. That localizes your search terms, so queries for "weather" or "coffee" pull up results close to you, and save you from typing those extra five digits every time you search for something nearby. Likewise, the My Location feature on the desktop uses information from nearby wireless hot spots to point you out.
I'm no fan of toolbars, believe me (well, maybe RoboForm) and I don't regularly use IE as my go-to browser, but for Google's My Location would the sacrifice be worth it? Truth be told, no, not for me at this point, but I might be tempted to try the souped-up toolbar were it to come out as a Firefox add-on down the road, or maybe switch to Chrome for a while if that were a built-in feature, not a toolbar.
How about you? Is having Google's search gods know where to route your queries a compelling enough feature to warrant downloading a toolbar--yes or no? And does privacy matter? Keep in mind that in using this Labs toolbar, you'll be sharing information with Google.