These are a bunch of tools that i have found useful over the period of time ive been online.

SEO Tools

http://www.iwebtool.com/tools/ is one of the best tool sets around on the web for checking nearly everything you could ask for.

http://www.webconfs.com/ Another half decent page of tools.

http://www.seochat.com/seo-tools/ And Another

The Three Tools sites above will tell you similar results and are very good as an out look into how you are doing but you should never take the results as absolute results they are not 100% accurate.

Another good tool has to be Shoemoneys Serps checker found here :

http://www.shoemoney.com/serps.php

Brilliant tool but only checks the .com sites not the .co.uk that i use most but for alot of you this will be fine.

Now for the forums that provided everyone with a little info from time to time, in my eyes the only ones i use for webmaster/seo stuff is my selected 5

http://forums.digitalpoint.com/

http://www.sitepoint.com/forums/

http://forums.ukwebmasterworld.com/

http://talk.iwebtool.com/

and of course http://www.qdoos.com

Valuation and Link Checkers

http://www.smartpagerank.com/

http://www.dnscoop.com/

http://www.backlinkwatch.com/

Directory Lists

http://www.strongestlinks.com/directories.php

http://www.seocompany.ca/directory/w...ory-lists.html

http://www.directorycritic.com/

Social Bookmarking

http://del.icio.us/ PageRank: 8/10
http://www.furl.net/ PageRank: 7/10
http://www.simpy.com/ PageRank: 7/10
http://del.icio.us/ PageRank: 8/10
http://www.backflip.com/ PageRank: 6/10
http://www.blinklist.com/ PageRank: 6/10
http://bluedot.us/ PageRank: 6/10
http://de.lirio.us/bookmarks/ PageRank: 6/10
http://www.diigo.com/user/ PageRank: 6/10
http://www.shadows.com/ PageRank: 6/10
http://www.markaboo.com/ PageRank: 5/10
http://ma.gnolia.com/ PageRank: 7/10
http://linkagogo.com/ PageRank: 7/10
http://netvouz.com/ PageRank: 7/10
http://www.mister-wong.de/ PageRank: 6/10
http://www.spurl.net/ PageRank: 7/10
http://www.rawsugar.com/ PageRank: 6/10
http://www.stumbleupon.com/ PageRank: 7/10
http://www.digg.com/ PageRank: 8/10
http://www.blogmarks.net/ PageRank: 7/10
http://myweb2.search.yahoo.com/ PageRank: 7/10
http://www.netvouz.com/ PageRank: 7/10
http://www.taggly.com/ PageRank: 5/10
http://www.lookmarks.com/ PageRank: 5/10
http://socialbookmarking.org/

This is the top 25 in my eyes in terms of amount of traffic they bring my sites.

PR and Fake PR Checkers

http://www.digpagerank.com/

http://www.seologs.com/pr-check/pagerank.html?url=


SEO Ratings Site quite good as a basic Guide

http://www.instantposition.com/seotest.php

Also this SERPS software is quite good for a quick look

http://www.serpcrawler.com/