If your internet usage consists of reading the odd email - you can disregard this list. But if you, like me, run a startup, a blog or podcast you should be using each of these 5 very important tools:
Gmail - This is a no brainer. Having your email in the cloud is essential for communications and networking online. Although checking you email every 5 minutes is stupid, having the ability to access emails whereever you are using whatever device is a must have. Combine Gmail with Google Desktop for quick and easy email searches.
Twitter - Don't be a doofus (is that how you spell it) and just use twitter to post links to your blog articles, use it as the powerful comminications tool is has turned out to be. With Twitter you can connect with friends or reach out to a broader audience and gain valuable insight current affairs. If you use Twitter correctly, you will have all the buzz you need!
Wordpress - I have a Twitter, Digg, Flickr, Youtube, Friendfeed, Facebook, MySpace, Linkedin, Pownce etc. account. What I need is a homebase, somewhere to organise and present my various thoughts and link out to my social profiles. A blog is a great start. Use Wordpress daily - post links, pictures, articles and videos - add value to the internet. Your blog is your brand!
Del.icio.us - I used to use my browser to organise my bookmarks. Then I woke up, decided to use Delicious and never looked back. I need Delicious, I browse through many if not a hundred+ sites a day and using Delicious I never seem to lose track of that site I was planning to review. Again don't be a doofus and boomark your own sites, you're not going to forget them.
Google Reader - How do you read 100+ blogs daily? Use Google Reader and learn to skim. Reader does a good job of organising my RSS feeds plus I can blast out any stories I like using its social features.
And one you shouldn't be using - Instant Messenger - Hey, you've got Twitter and Gmail now (gmail has built in chat) so forget about using a desktop messenger. It is the most unproductive way to communicate. Sure its instant, but life isn't, so slow down a bit and use email + twitter (oh and that thing called a telephone).
Image Credit - jonas_therkildsen' s