Sony's PEG-SJ33 is an updated version of the PEG-SJ30 that it launched in mid-2002. The most obvious difference to the eye is a series of colourful, hard plastic screen covers available with the SJ33.
The latest model has a processor that is twice as fast as that in the SJ30 - a 66MHz version of Motorola's Dragonball Super VZ - and a longer-life battery.
The 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 72.5mm by 107.8mm by 22mm, making it slightly longer, wider and deeper than the SJ30.
Other features include PalmOS 4.1, 16Mbytes of memory of which 15Mbytes is available to the user, a Memory Stick slot, USB and infrared ports and a 320-pixel by 320-pixel colour TFT LCD. The SJ33 does not support Sony's recently introduced Memory Stick Pro memory card format.
Sony's PDA will go on sale in Japan next month for around ¥30,000 (£155). Details for other markets will be announced soon.
Casio's Cassiopea E-3000 has been given a facelift but it has much in common with the E-2000 model that was launched about year ago.
The biggest change is a faster processor, based around a 400MHz version of Intel's XScale processor. Other features of the Pocket PC 2002 operating system-based device include 64Mbytes 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 78mm by 130mm by 17.5mm. Casio will launch the E-3000 in Japan in late March for around ¥60,000, but there are no plans to launch it overseas.