Just a quick list of online scanners - will try to update regularly - please post or send me an email if you have other great links!
General scanner (very cool):
http://virusscan.jotti.org/
File/Machine scanning:
http://housecall65.trendmicro.com
http://www.pandasecurity.com/homeusers/solutions/activescan
http://www.bitdefender.com/scan8/ie.html
http://security.symantec.com/sscv6/default.asp?langid=ie&venid=sym
http://support.f-secure.com/enu/home/ols.shtml
http://onlinescan.avast.com
http://www.kaspersky.com/scanforvirus
http://www.eset.com/onlinescan
http://www.virustotal.com
Microsoft Malicious Software Removal Tool
http://www.microsoft.com/security/malwareremove/default.mspx
GFI EndPointScan
http://www.endpointscan.com/
Acunetix WVS (is your website hackable?)
http://www.acunetix.com/cross-site-scripting/scanner.htm
Test email system
http://www.windowsecurity.com/emailsecuritytest
