MzScheme-Yahoo-Web-Search is a project mainly written in Scheme, it's free.
MzScheme module for using the Yahoo! Web Search API
Something I messed around with a long time ago when the Yahoo! Web Search API first came out and before MzScheme became Racket.
I have very, very little experience with Scheme so this is likely to possess a high degree of suckiness.
Sample usage from the MzScheme REPL:
$ mzscheme
Welcome to MzScheme v4.1.5 [3m], Copyright (c) 2004-2009 PLT Scheme Inc.
> (require "yahoo-web-search.scm")
> (for-each-result (lambda (x) (printf "~a~n" x)) "query=mzscheme")
((Title () MzScheme) (Summary () The MzScheme package is a subset of the PLT Scheme package; it contains MzScheme
and console applications based on it, including the PLT web server, ...) (Url ()
http://www.plt-scheme.org/software/mzscheme/) (ClickUrl () http://www.plt-scheme.org/software/mzscheme/)
(DisplayUrl () www.plt-scheme.org/software/mzscheme/) (ModificationDate () 1279695600) (MimeType () text/html)
(Cache () (Url () http://uk.wrs.yahoo.com/_ylt=A0PDBgnePVRMaAsAXDLdmMwF;_ylu=X3oDMTBwOHA5a2tvBGNvbG8DdwRwb3MDMQRzZWMDc3IEdnRpZAM-/SIG=15tetuk3j/EXP=1280675678/**http%3A//66.218.69.11/search/cache%3Fei=UTF-8%26appid=YahooDemo%26query=mzscheme%26u=www.plt-scheme.org/software/mzscheme/%26w=mzscheme%26d=P5ZODbZfVNYw%26icp=1%26.intl=us)
(Size () 3578)) )
...I have not tested this with Racket.