Sony Ericsson has been showing off a 12.1Mp touchscreen cameraphone at Mobile World Congress. Commonly known as the Idou, the prototype phone has a 3.5in touchscreen in the 16:9 widescreen format and a Xenon flash.

As with the Xperia X1, which Sony Ericsson unveiled at Mobile World Congress last year, the 12.1Mp cameraphone is many months from launch. The mobile phone manufacturer says Idou is only the handset's concept name. The phone will go onsale in the second half of 2009.

Keeping the momentum going from now until then will be a challenge for Sony Ericsson, according to Ben Wood, analyst at CCS Insight. It also gives competitors like Samsung the opportunity to launch and start selling devices with similar specifications ahead of Sony Ericsson, he said.

Sony Ericsson W995

The Idou is based on what will become the Symbian Foundation operating system; the upcoming open source version of the Symbian operating system. It competes with the Google-backed Android platform, for example. Sony Ericsson is working on a phone based on that platform as well, but isn't ready to announce any details yet.

Closer to being in stores is the W995 Walkman, which will be available during the second quarter. The phone comes with an 8.1-megapixel camera, support for AGPS (Assisted Global Positioning System) and a bunch of music features, including a 3.5mm audio jack. It surfs the using either Wi-Fi or HSPA (High-Speed Packet Access). Pricing was not announced.

Many upcoming Sony Ericsson phones will, just like the W995, combine music and camera plus also something extra - which, for example, can be support for watching movies on the device.

Sony Ericsson is also working on a movie download service, which eventually will fall under the Play Now umbrella. But yet again Sony Ericsson is frugal with the details.