At Mobile World Congress in Barcelona Acer has revealed a quartet of handsets that straddle the feature phone/smartphone divide. There's the beTouch E110, the beTouch E400 (pictured above), the neoTouch1 P300 and the neoTouch1 P400. In France and the USA the latter two handsets will confusingly be called the newTouch P300 and P400.

Starting at the low end, the beTouch E110 is an Android handset which offers a 2.8-inch touchscreen, 416MHz processor, 3.2-megapixel camera, headphone jack, Bluetooth 1.0, GPS, MicroSD slot and FM radio. There's no Wi-Fi and bizarrely it's running Android 1.5 - albeit complemented with Acer's homegrown UI additions - music, social networks and five homescreens. It'll be arriving in March in black and dark blue.

Next up is the beTouch E400 - another Android device, but this time running Android 2.1. Inside there's a 600MHz Qualcomm chip, a 3.2-megapixel camera, b/g Wi-Fi. Bluetooth 2.0, GPS, MicroSD, a headphone jack and a 3.2-inch touchscreen. Unfortunately that touchscreen is of the resistive variety - not as sensitive as the capacitive type found on most other handsets. It comes with three different battery covers - black, white and red. It'll show up in April.

Moving on up, the Acer neoTouch P300 is a Windows Mobile 6.5.3 device with a 3.2-inch touchscreen and slide-out full QWERTY keyboard. It has a Qualcomm 528MHz CPU, b/g Wi-Fi, Bluetooth 2.0, GPS, MicroSD slot, headphone jack, and 3.2-megapixel camera. It's pre-loaded with Acer's apps, including one which adds social networking support to the contact book, and there's the regular Windows Mobile apps too - Exchange support, IM and the Flash-supporting IE6. It'll be available from March.

Lastly, the Acer neoTouch P400 also runs Windows Mobile 6.5.3, offering a 3.2-inch touchscreen, Qualcomm 600MHz processor, b/g Wi-Fi, Bluetooth 2.1, GPS, microSD slot, headphone jack and 3.2-megapixel camera. It has an onboard compass and accelerometer, too. On the software side, you've got IE6 with Flash, Bing search, Windows Media Player 10 and a dedicated YouTube app. It'll be landing in May.

Four handsets, two running Android and two running Windows Mobile. Do any of them float your boat? Let us know in the comments.