Userscripts.org

Show/hide the header, footer and sidebar tabs on iGoogle to save space! Perfect for small screens or netbooks!

Shows the number of unread Gmail messages in the FavIcon in your Firefox tab.

Adds icons for Mail, Profile, Favourites, Scout, Interestingness, DNA, and the user's photo archive next to usernames in forums and on individual photo pages. It also allows you to send Flickr Mails without leaving the current page you are on.

Makes "mailto" links open in your favorite web-based email account, instead of a pop-3 client (like Outlook, Eudora, Thunderbird, etc.) Supports Gmail, Yahoo Mail, and Google Apps Mail. [UPDATED Dec 2011]

Like labels? Like folders? LabelLinks4Gmail allows you to label your labels as well as your emails, combining the best of both worlds.

Turn plain text links into real clikable links. Attempts to catch links like google.com. Doesn't linkify emails. Edited by JoeSimmons.

[v0.53] Automatically skips any sponsored links (and optionally tips) detected in the Gmail Web Clips feed. Also optionally hides the sidebar that includes adverts when viewing an email thread.

OGame Alarm, sends email and audio alarm when attacked. Plus audio alarm for messages and espionage. Version : 3.4 (02/08/2013)

Finds information from Facebook, Myspace, Yahoo Messenger, Google Profiles, Picasa, etc. for all e-mail addresses found in a page and displays them on mouse-over.

Adds a nice touch to your Gmail account. [UPDATED]

Forces all mailto links to open in GMail

Gmail + "Cloud Computing" = Gmail 3.0. Use Gmail to increase your online productivity. G3.0 (jee Three pee ohh) New Video.

Replace GMail classic superstars (which you can enable in GMail labs settings) by meaningful icons (place/dollar/sport/etc.) so you can quickly retrieve your emails by topic.

Cleaner version of Windows Live Mail

Adds some options to help manage your Flickr mailbox. Including "Mark all as read" and delete all Notification emails, such as "you are x's newest contact" and Group Invitations, and also a "Nuke mailbox" function, that deletes all your mails

Stops hotmail redirecting you to msn when you sign out

Shows eBay items on a Google Map. Links from search results and item pages.

[1]Turn plain text URLs into links.[2]Supports http, https, ftp, email addresses.[3]Very helpful when visiting websites like pastebin and tinypaste

Adds functionality during message composition to support multiple from addresses. I've begun internationalization. Any translations would be helpful.

Lets admins delete images from a group pool with 1 click, also lets you delete all a users images from the pool at once + also allows you to email + optionally ban or kick a user at the same time.

Turns plain text URLs, email addresses, and Twitter links (@twitterID) into links. You can add new filters if you know how to use JavaScript regular expressions. (Only Twitter links are new in this modified version.)

Ever wanted to share a cool website to the world but didn't know how? With this script, you can easily email, subscribe, bookmark and share over dozens of networks!

Remove the (irrelevant) ads sidebar from Gmail message view allowing more width for the actual message.

Secure the Connection on: Excite, Yahoo, Gmail, Microsoft Passport. (Add any site to the Included pages list for it to be automatically switch to secure mode as well)

Turns even heavily munged (spammer-protected) e-mail addresses into a link.

Automatically login to Yahoo!Mail

Quickly post any page to common online services

Makes craigslist emails go to Gmail instead of the default mail service

Totals the installs, comments and fans on userscripts profiles.

Quickly create disposable email addresses on any web site