If you click on "Advanced Search" and just enter a query to search, you end up with a ridiculously long url, e.g.,

http://www.google.com/search?num=10&lr=&as_ft=i&as_filetype=
&as_qdr=all&as_occt=any&as_dt=i&as_rights=&as_q=google&hl=en&
btnG=Google+Search&as_epq=&as_oq=&as_eq=&as_nlo=&as_nhi=&
as_sitesearch=&safe=images

Here's what all those fun parameters mean, and any keyword equivalents I noticed:

as_q: with all of the words
*equiv: implicit, or – (not), . (and), | (or), () (phrase)

as_epq: with the exact phrase
*equiv: "q1 q2" or q1-q2

as_oq: with at least one of the words
*equiv: implicit, or +q1

as_eq: without the words
*equiv: -q1

num: number of results

hl: language (this is a hidden input on google.com)

lr: also language

btnG: Google Search (well no kidding...)

as_ft: only/don't use the specified format

as_filetype: pick your file format
*equiv: filetype

as_qdr: time range, default=all
*equiv: daterange:julianstart-julian-end

as_nlo, as_nhi: hi and low numbers for numrange search
*equiv: 1..99

as_occt: where the results should occur, default=any
*equiv: allintext,intitle,allintitle,allinurl,inurl,allinurl,allinlinks
*intitle/inurl is to words as allintitle/allinurl is to phrases

as_dt: only/dont get results from this domain, default=i

as_sitesearch: domain to/not-to search
*equiv: site:website.com

as_rights: license search

sfio: safesearch bullets

as_rq: similar to this site
*equiv: related

as_lq: links to this site
*equiv: link

cache: cache of this site
*equiv: "cache:blog.outer-court.com"

btnl: i'm feeling lucky

q: search query

Thanks for the info!

The btnG is always annoying... especially since it means you can't copy & paste normal Google search result URLs, you always have to change the & to &.

Cool list. Thanks for the info

If you search from the Firefox search box, you don't get the btnG in the results URL. Also, the other parameters are at the end of the URL (after the query string), making it much easier to chop them off leaving just the query string.