I am currently using the following bookmarklets (or favlets). Just drag these links to your browser bookmark toolbar and you are done. If you have never used bookmarklets before, here's a quick video tutorial on how to install Bookmarklets to your Browser.
post to del.icio.us - tag the current webpage and save it to del.icio.us.
coComment! - Click the coComment button before submitting your comment on a supported blog - coComment will copy your comment and list it in the "your conversations" page on coComment.
Watch It! - I use ChangeNotes to monitors web pages and this bookmarklet quickly adds the current website to my watch list.
Sphere it ! - Sphere is a new blog search engine that returns webpages related to the content of the current webpage.
TinyURL! - Creates a short URL of the page you are currently at. Useful when you sending someone a lengthy link by email.
Technorati This - Helps you find who is linking to the current page or blogging about the selected text on Technorati.
[toread] - ToRead.cc sends the current webpage to your email inbox with all the formatting and layout intact.
Furl! - Save the current webpage to Furl .
GMail This! - Select some text on the webpage and click the GMailThis bookmarklet to compose a new GMail message in a new window.
Blog This! - If you have a blog on blogspot.com, this bookmarklet is for you. BlogThis! is an easy way to make a blog post without visiting blogger.com. Clicking BlogThis! creates a mini-interface to Blogger prepopulated with a link to the web page you are visiting, as well as any text you have highlighted on that page.
Earlier, I also had some bookmarklets to add feeds with autodiscovery tags in Newsgator and Bloglines but now I use Google Toolbar for subscribing to feeds.
1. Bookmarklets for iPhone and iPad
2. Bookmarklets for Chrome, IE and Firefox