The Xperia Sola - which was unveiled towards the end of March 2012 - is the Xperia U done well.
While you can get the latter refurbished and locked to O2 on PAYG for £79 plus a top up voucher, the Xperia Sola is available from Sony direct for £141 including delivery (note that a 20 per cent discount will be applied at checkout)
The biggest difference compared to its little brother is the fact that it has a microSD card slot.
Other features include a dual-core ST-Ericsson Novathor U8500 SoC clocked at 1GHz, 512MB of RAM, 8GB onboard storage, a 3.7in 854 x 480 pixel screen with Reality Display and Mobile Bravia engine, a 5-megapxiel camera with 3D sweep panorama and HD video recording and up to six hours talk time/40 hours of music listening time.
Connectivity options include Android 4.0 ICS, a microUSB port, DLNA certification, Wi-Fi, Bluetooth and NFC. At 107g and with a thickness of only 9.9mm, the Xperia Sola is tiny compared to recent mainstream handsets like the LG Nexus 4.
Sony has added some interesting goodies like the TrackID music recognition, xLoud audio filter technology, Android 4.0 ICS with the Timescape user interface. Check out the review of the Sony Xperia U.