They make Gmail easier to use are starting to pop up on the web, here are the ones I've found so far:

Official Gmail Notifier from Google (beta) - Downloadable Windows application that alerts you when you have new Gmail messages.
Gmail Search Extension - Search your Gmail account from the Firefox search bar
Gmail Tray - A search box for the Windows taskbar
Gmail Notifier - Firefox extension, installs an icon on your toolbar that displays the amount of new messages in your inbox (previous post)
Gmail-to - Associate all mailto: links with Gmail as opposed to Outlook
Gmail-to Bookmarklet - Compose messages from your Gmail account from any page (previous post)
Gmailit - Bookmarklet to send the current page you're viewing to someone through Gmail
GMail Loader (GML) - Cross platform application forwards your existing email to Gmail
Pop Goes the GMail - Gmail > POP3 converter
gExodus - Graphical user interface tool allows you to import your emails into your Gmail account.
gCount - a menu bar item for Mac OS X 10.3 or later that displays the number of unread messages in the inbox (Via Google Blogoscoped)
GMail, RSS Feeds - Retrieve notifications of new mail through RSS
Gmail as online backup system - .php script to back up files to Gmail and retrieve them
Gmail in Opera - Use Gmail with the Opera browser, which currently is unsupported
Gmail Gems - Tips and Tricks to use Gmail more efficiently
Unread Gmail - Create a label called "Unread", Gmail will automatically add all unread items to it (Via Gmail Wiki)
PINE Addressbook to Gmail - Export addressbook in CSV format from PINE to Gmail. Via here
GmailFS - Gmail Filesystem - GmailFS provides a mountable Linux filesystem which uses your Gmail account as its storage medium. (Via Scripting.com)
GSuite - Lets you access and use Gmail from a mini-browser in the system tray
GmailStatus - Shows the number of unread messages in the Mac OSX menubar
gmail copy - Command line utility to copy files to and from gmail (Via del.icio.us)
GMailer (libgmailer) - A PHP library/class that helps you accessing/checking/using GMail through PHP scripts. (A blog that uses this to convert Gmail messages into the blog posts)
Gmail icon generator - Create an image of your Gmail address to minimize spam exposure (Via here)
Gmail Agent API - Open Source extensible foundation for interfacing with Gmail. Written for .NET framework
原文网址：http://www.igniq.com/robs_blog/2004/06/gmail-tools-plugins.html