The Yendo has just the bare bones feature wise, not all of them work well either.
For connectivity we have only the 2G GSM networks of GPRS and EDGE, their frequencies are GSM; 900/1800, GPRS; 850/1900. At least the Yendo is smart enough to recognize which is which and switches automatically if the network changes. Local connectivity is supplied via Bluetooth v2.1 with AD2P and v2.0 microUSB, there is no Wi-Fi at all. The Yendo has the smallest internal memory of any phone I have ever reviewed, a truly miserly 5MB, at best you could store one medium quality song. The processor is an almost useless 156 MHz.
Now we take a look at the Yendo's main party piece, the music player. For Sony Ericsson's first ever fully music orientated touchscreen device, the Yendo is a fail. The music player is bare bones in nature, no 5.1 surround or 3D playback, hell even the equalizer setting are buried truly deep into the sub-menu. Sound quality is above average though, but this is not a remarkable feat at all, even phones with no real musical orientation have fantastic playback. Almost all musical formats are played, it is a Walkman after all.
The TrackID feature works well enough, as does the FM radio with RDS. All music based menus are simple and elegant, the radio even has a handy way of tagging stations, it creates small "notches" on available stations once they have been scanned so you can get to them easily.
Now for the 2 MP camera, it is hardly worth using, at best use it for emergency snaps but otherwise stick to your normal camera. It has a maximum resolution of 1600 x 1200 pixels, no auto focus and definitely no flash. Pictures have a very high level of noise and there is almost no fine detail in outdoor shots, there is no Geo-Tagging or anything fancy. The camera UI is simple and serviceable, it feels like a blue knock-off of Samsung's TOUCHWIZ camera UI.
The gallery is not bad, you only get grid view which is organized by date, plus the blatant rip-off of Samsung One Touch Zoom. Videos are shot at a surprising 30 FPS but are shot in QVGA unfortunately, also they are recorded in 3GP format and not MP4, so the videos are worth strictly MMS purposes only. The video player itself is a big letdown, it only plays MP4 files encoded in H.263, or plain good old 3GP work as well. Remember to play videos encoded in a resolution beneath the phone's native resolution for the best playback quality.
The Yendo has a full set of organizer apps, all of which work very well. They are; Voice memo, Document Viewer, Predictive text input, JAVA MIDP 2.0, Alarm, Stopwatch, Calendar, Calculator, Timer, Facebook and finally Twitter. The Yendo does come with MicroUSB charging.