To disable favicons in Firefox, open the browser and type about:config into the URL bar, then press Return. You may then see a warning about how modifying advanced settings may void your warranty; click the “I’ll be careful, I promise” button to proceed anyway. You’ll now be looking at a long list of preferences, along with their status, type, and value. In the Filter box above the list, type browser.chrome; this will greatly shorten the list of preferences.

In the resulting list, double-click on browser.chrome.favicons to change its value from true to false. Then double-click on browser.chrome.site_icons, to set that preference to false, too. That’s it; you’re done. From now on, you’ll no longer see favicons as you surf the net.

To reset things to normal, just reverse the process–go back into about:config and double-click the same two preferences again to set them back to true.

For Safari, first quit the browser, then open Terminal (in Applications -> Utilities), and type this command:

defaults write.com.apple.Safari WebIconDatabaseEnabled -bool NO

Relaunch Safari, and you’ll be browsing favicon-free. To undo this trick in Safari, quit the browser, open Terminal again, and repeat the above command, but replace NO with YES. I’ve tested the solutions in both Firefox and Safari, and they work as described–though I did reverse the settings after testing, as I really do prefer to see the favicons.

For example, remember the Google Accelerator, which was supposed to speed up Web surfing? (A dubious claim, but least it was free.) But you had to pay to get a Google Answer, and eventually people stopped asking. Google Video did so well that the company finally gave up and shelled out big bucks to buy YouTube. If you can’t beat ‘em, buy ‘em.

Some Google flops lasted no more than a day and then vanished without a trace. Other Google efforts have been left to languish like a neglected orphan inside Google’s labyrinth of Web services. Still other dogs were released as betas nearly five years ago and are still trapped in Google Labs with apparently little hope of escaping the test tube.

Our list of Google’s lead balloons is by no means exhaustive; if you have other candidates, by all means, point them out in our comments section below.

New beta 19 percent faster in rendering JavaScript than last preview.

The milestone features more work under the hood — particularly in stability and performance of the new TraceMonkey JavaScript engine — as well as tweaks to the private browsing mode and improvements to the underlying Gecko layout engine, said Mike Beltzner, director of Firefox.

Computerworld’s tests showed that Firefox 3.5 Beta 4 is about 19% faster than Beta 4 in the SunSpider JavaScript benchmark; both betas were considerably faster than the production browser, Firefox 3.0.10, which was also released yesterday.

Other enhancements, said Beltzner in a message posted to the mozilla.dev.planning forum, have been made to Firefox’s new location awareness feature, and support for Web worker threads — an enhanced scripting functionality that lets site developers shift JavaScript computations to a background thread — has been completed.

As it usually does, Mozilla warned users that Beta 4 is suitable for testing only. “Firefox 3.5 Beta 4 is a public preview release intended for developer testing and community feedback,” said Beltzner. We recommend that you read the release notes and known issues before installing this beta.”

The beta’s release notes highlighted several still-unfixed issues with Firefox 3.5, including problems with Gmail, Google Inc.’s popular Web-based e-mail service, and with parts of the new privacy feature.

Beta 4 is the first major milestone of Mozilla’s new browser to carry the “3.5″ moniker; originally, the upgrade was called Firefox 3.1, but the company decided it had added enough new features to justify the larger bump in version number from last summer’s Firefox 3.0.

Those additional features — especially TraceMonkey — caused some delays last year as Mozilla worked to both integrate the new JavaScript engine and test it. Other delays were the result of troublesome bugs, many of them also in TraceMonkey.

Although Mozilla said much earlier in the Firefox 3.5 process that it would ship a limited number of betas before moving on to a “release candidate,” it’s unclear today what Mozilla’s next step will be. Attempts to reach Beltzner via e-mail were unsuccessful.

In 2008, the company issued the last beta of Firefox 3.0 in early April, and the final version in mid-June. Assuming Firefox 3.5’s pace is similar, Mozilla should ship Firefox 3.5 sometime in early July.

Firefox 3.5 Beta 4 can be downloaded for Windows, Mac OS X and Linux in 63 different languages from Mozilla’s site. Users already running Beta 3 will be notified of the available update in the next 48 hours.