Sony and Casio have unveiled improved versions of PDAs they each launched in 2002.Sony's PEG-SJ33 is an updated model of the PEG-SJ30 that it launched in mid-2002. The most obvious difference to the eye is a series of colorful, hard plastic screen covers available with the SJ33. Sony has black, orange and blue covers available to make the SJ33 appear a much more colorful PDA than its predecessor.Under the hood, there are a couple of big differences. The new model has a processor that is twice as fast as that in the SJ30 - a 66 MHz version of Motorola's Dragonball Super VZ - and a longer life battery has also been added, Sony said in a statement.Sony says its rechargeable battery pack, fully charged, can provide enough power for 17 days of use assuming average use of 30 minutes per day with the screen's backlight switched off. There are no figures available for battery life with the backlight switched on, which is the way most people use their PDAs.The larger battery and hard cover has had a big impact on the weight of the device, which is 220 grams against 137 grams for the SJ30. It measures 72.5 millimeters by 107.8 millimeters by 22 millimeters which is slightly longer, wider and deeper than the SJ30.Other features are similar and include PalmOS 4.1, 16M bytes of memory of which 15M bytes is available to the user, a Memory Stick slot, USB and infrared ports and a 320-pixel by 320-pixel color TFT LCD. The SJ33 does not support Sony's recently introduced Memory Stick Pro memory card format.It will go on sale in Japan during February for around \u00a530,000 ($253). A version with a black cover will be available from Feb. 8 while versions with orange and blue covers will be available from Feb. 22. Sony on Monday announced plans to launch the SJ33 shortly in Hong Kong for HK$2,480 ($320) and says details for other markets will be announced soon.Casio's new Cassiopea E-3000 has been given a face-lift but specification-wise has much in common with the E-2000 model that was launched around one year ago.The biggest change is a faster processor. The E-3000 is based around a 400MHz version of Intel's XScale processor, it said in a statement. Other features of the Pocket PC 2002 operating system-based device include 64M bytes of memory, a 240-pixel by 320-pixel 3.5-inch TFT LCD, Compact Flash slot and Secure Digital (SD)\/Multimedia Card (MMC) slot.Battery life of the standard rechargeable pack has been extended to 15 hours. The E-3000 measures 78 millimeters by 130 millimeters by 17.5 millimeters. Casio plans to launch the E-3000 in Japan in late March for around \u00a560,000. There are no plans to launch it overseas, the company said.