I think it's time for me to start what you might call an "advice" topic.
That's because I was browsing the web a lot these days and I found so many websites I coulnd't properly view with Firefox (that's what I am using).
The other reason is that someone asked here whether W3C standards help with the SERP. Well, they do, somehow... but you still need to compete with websites that have better content, better linking strategies. The W3C standards are just tools you can use to create the best website: a user friendly, functional and "best viewed with all browsers" website.
So design your websites with all the browsers in mind.
That's really important for your online business.
To learn more, visit these links:
http://www.anybrowser.org/campaign/http://www.anybrowser.org/campaign/abdesign.htmlhttp://www.anybrowser.com/