Here are some pretty nifty Google search parameters to help you with your SEO efforts.
Adding &pws=0 turns off personalized search.
If you work with clients in a region other than your own, localization could come in handy.
gl – country &gl=US
gll – latitude,longitude
gr – region &gr=CA-AB &gr=GB-ENG &gr=US-UT
gcs – city (gr must be set) &gr=UT-US&gcs=Salt Lake City
gpc – postal code (gl must be “US”) &gl=US&gps=84109
gm – US metropolitan areas &gm=770
Restrict search results to a date range by using as_qdr.
d[number] – past number of days (i.e. &as_qdr=d10)
w[number] – past number of weeks
y[number] – past number of years
Joost de Valk created a very nice pdf summarizing several of the google url parameters. You should also check out Cheat Sheet For Google Cheat Sheets for a few more links.