If you run an exchange server and have trouble keeping off blacklists, this is a great site to check out – they have news about all the popular DNSBLs and some great articles about keeping your server off of blacklists – definitely worth checking out!
http://www.websiteoptimization.com/services/analyze/
This is a great tool that puts another light on search engine optimisation – as most people will know, Google has recently confirmed the completion of its new search index – Google Caffine, which takes the speed of a website much more seriously. The link above will take you to a great (and free) online tool that will test the speed of your website – and the factors that effect the result – it will detail for you the size of your page, the amount of objects on the page, size of css,images,javascript etc and it also gives you advise on how to optimise your site for speed.
The great thing about this tool is that once you start reading the recommendations, you get enveloped in it – I ended up learning about, and implimenting CSS Sprites, optimising external JS files and removing space amongst other things.
Lastly, I love the websites layout, its actually a very basic design, but I think it looks great – and its one of those websites you can tell has been built on functionality, whats more, it actually validates – which isnt seen much these days!!!
This is a great bit of information I came across recently which describes the default formating of elements in HTML4 – it came in handy for me today as I had a heading set up as H3 – but I wanted to change this to a span (for SEO purposes) without loosing the current formating. With this info, all I had to do was copy the default styling to my span.class and I was done!!
Take a look: http://www.w3.org/TR/CSS2/sample.html