Are you still using Firefox 1.5 or Internet Explorer 6? If so, it’s time to start seriously thinking about an upgrade.
Firefox 1.5 reached the end of its life today. That means that security and other fixes will only be available for Firefox 2 and later. Firefox 2 will run on all the same systems as the version you have right now, plus it gives you enhancements like spell check, phishing protection, and improvements to the features you already use.
Internet Explorer 6 is outmoded. It has limited support for the languages that make up the web (particularly CSS), and often disagrees with every other browser out there, forcing developers to write complicated code so that it will work on IE6. If you’re running Windows XP, you can upgrade to Internet Explorer 7. If you’re running an older version of Windows, you can benefit by switching to an alternative browser such as Firefox
or Opera. Whether you switch or upgrade, I highly recommend moving away from Internet Explorer 6.
Update: Mozilla has extended Firefox 1.5 support through mid-May.