If any single feature in the new Firefox 4 could be described as "killer," it's Firefox Sync. Originally launched as a buggy add-on called Mozilla Weave several years ago, it now comes baked directly into Firefox and with all its creases ironed out. It will synchronize your bookmarks, passwords, preferences, history, and tabs across not only multiple computers, but your Android and Maemo phones and tablets, too.

Check out the procedure for linking up Firefox on all your digital toys in this How To video, and if you have any questions about Sync, let me know in the comments below.

So the rumors were true: Research In Motion announced today it will allow Android apps on its yet-to-be-released tablet, the PlayBook.

The forthcoming tablet will have "app players" that will run BlackBerry apps created in Java, and apps created for Android 2.3.

Having the option of downloading Android apps on BlackBerry App World "will provide our users with an even greater choice of apps and will also showcase the versatility of the platform," Mike Lazaridis, president and co-CEO of RIM, said in a statement.

For developers working on apps, RIM says a "high degree of API compatibility" makes it easy to port BlackBerry Java and Android apps to the BlackBerry Tablet OS that will run on the PlayBook.

Word began to spread that RIM was thinking of allowing Android apps on its tablet starting in January. Many dismissed it because RIM had spent a lot of money to buy QNX, which makes the software on which the BlackBerry Tablet OS is built, and because it had done so much work with its own BlackBerry developer community.

RIM announced a 32 percent increase in quarterly earnings today, but warned of weakness in the coming quarter.

Originally posted at Circuit Breaker