validator.w3.org - validate your website
network-tools - trace server and dns
domaintools - extended who is
html-kit - web based favicon maker
hotscripts - scripts and software
chipmunk-scripts - tools and scripts
cutandpaste - free scripts
geekvillage - webmaster forum and tools
validator.w3.org - check outbound links
netcraft - check server uptime
smileytraffic - get traffic
whatismyipaddress - trace email and ip

soon more ...