A bookmarklet is a browser shortcut that runs a small JavaScript script, adding useful and immediate functionality to whatever page you might be browsing at the time.

There are many, many to be found on the internet – the site marklets.com is a rather complete collection of around 1000 that you can use.

However, one of the most useful bookmarklet related sites is the Bookmarklet Combiner, which lets you generate your own Bookmarklet, consisting of links to others that you specify.

But, to save you the hassle of searching, here are 21 I’ve found to be the most useful. To use any of them, simply drag the name to your Bookmark list at the top of the browser.

Modify Page

1. PageZipper
This appends multiple pages together to form one, continuous page. Useful on blogs, for instance, where a post may be over divided into multiple pages. [Homepage]

2. PrintWhatYouLike
If you wish to print a page, this lets you modify exactly what you want – turn off background printing and images, for instance. You can even mark which part of this screen requires printing. [Homepage]

3. Readability
This lets you strip everything on a website you are viewing but the content of the article itself. Again, useful for blog reading. [Homepage]

4. Remove Bloat
This eliminates all occurrences of Flash, Java, music, and third-party iframes from a page. This can be particularly useful on those sites where browsing is reduced to a chore thanks to an over abundance of Flash animations!

Downloading

5. Bitlet
Click on the BitLet Bookmarklet when you want to add a “download by bitlet” link near a torrent you want to download. [No longer available]

6. ClipNabber
Download almost any video from any video sharing site. [Homepage]

Passwords

7. View Passwords
Display all passwords on the page that are otherwise not visible – e.g. those displaying as asterisks. [Homepage]

8. BugMeNot
Many sites often free access, but only after signing up to an account. BugMeNot is a service that provides shared signins to popular sites, saving you the hassle of having to sign up first. [Homepage]

9. SuperGenPass
SuperGenPass uses a hash algorithm to transform a master password into unique, complex passwords for the Web sites you visit. And because it’s a bookmarklet it never stores or transmits your passwords. [Homepage]

Web Development & Design

10. Design
Design is a suite of web-design and development assistive tools, encompassing utilities for grid layout, measurement and alignment. [Homepage]

11. Firebug Lite
This is a cut-down version of the well-known Web Development tool, designed to work on other browsers other than Firefox. [Homepage]

12. WP Toolbar
Appends the default WordPress admin menu to whatever page you’re currently on (assuming you’re on a site that’s running WordPress) and styles it with CSS, fixing it to the top right corner. [Homepage]

URL Sharing

13. Email This
Email details of the current page to others. This doesn’t use your own email client, but the email is sent via its own site – simply provide your own email address. [Homepage]

14. Facebook Share
Send details of the current page to your Facebook account, read to share. [Homepage]

15. GmailThis!
Like Email This but uses your own Gmail account – a “Send” window appears with the site details pre-filled in. [Homepage]

Bookmark

16. TheThingsIWant
Save online product pages to the TheThingsIWant website, where you can share, view and buy. [Homepage]

17. Read It Later
Allows you to save the current URL to a special Read It Later account, which you can then view later. [Homepage]

Miscellaneous

18. FreezePage
Stores a copy of the web page that you’re looking at on their servers, for you to access later. [Homepage]

19. Translate
Use Google to translate the current page. [Homepage]

20. Bit.ly
The popular URL shortening service provides a neat sidebar where you can quickly create a short URL and even share it on Twitter [Homepage]

---

Update: Removed Centricle.com links as the site no longer exists. Also removed SuperGenPass bookmarklet from page as it was causing it to break – please use the link to the homepage to use it instead.