The Sony Vaio UX490 is the successor of Sony's flagship UMPC, the UX390. Find out below if this is an improvement.

Most of the design of the UX390 remained the same in the UX490 but internally it's a big upgrade. Most notably, the processor went from the old U1500 Core Solo to an U2200 Core 2 Solo CPU running at 1.2GHz. Another big change is the harddisk that went from a 32GB HDD to a 48GB SSD. The flash disk should give you some good battery savings. According to Sony it should save as much as 37% in comparison with a traditional HDD.

Continuing with the specs, the Sony Vaio UX490 offers connectivity through Wifi and Bluetooth. The unit also has an integrated Wide Area Network (WAN) to connect with the AT&T Edge network all around the USA.
The UMPC also packs two built-in camera's. One can be used for video-conferencing and the other for taking pictures.

A great feature compared to the UX390 is the extra large capacity battery that comes with the unit. This should really extend your battery life. According to Sony it should get you anything from 3 to 7 hours extra.
Another extra that comes with this box is the Bluetooth GPS adapter.

Some specs that don't differ much from the UX390 are the 1 USB port and 1 Ethernet port. It still has the keyboard with a sliding screen. With a weight of 1.2lbs it is light weight and the dimensions of 1.5, 5.91 and 3.74 inches make it a typical UMPC size. The same goes for the 4.5 inch LCD touch screen. Finally, the RAM is 1GB just like the 390 and the OS is Windows Vista Business.

To conclude this small review here are some pros and cons.
A real pro is the connectivity of the UMPC. With the integrated WAN, wifi, Bluetooth and added GPS you can take this to the road.
The SSD drive is also a big pro. It is bigger and more energy efficient which is obviously important with this type of mini pc's.
Some major cons are the price and the OS. The price of a Sony Vaio UX490 is still about $2500 staying on the same level from it's introduction in 2007. Compared with a lot of other UMPC's and especially netbooks and MID's, this is quite expensive. Another con is that the UX490 comes with Vista Business and this will not please everybody.

With the shift of the market and the introduction of netbooks and MID's this UMPC may very well be too expensive for what it has to offer.