The Acer c20 Pico Projector is about the same size as a modern SmartPhone but slighter thicker. It has a built-in battery so you can, in theory, use it without mains power. It comes with a charger and several cables/adapters to connect to various devices such as your laptop.
My initial idea was that it would be good to carry in place of a larger projector when doing small venue presentations, demonstrations or training. However I found that the connector to connect to a SmartPhone was an optional extra and when connected to a laptop the native resolution was less than the standard laptop screen so although the effective screen size was larger, the amount you could get on was less. I later found that better results were achievable if your laptop has an HDMI output in addition to the standard VGA output. However, in a normally lit office environment the image was also difficult to see clearly unless you beamed the image onto a screen close to the projector but this defeats the object and you may as well use a normal laptop screen or 19-21” TFT monitor.
Connecting the Acer c20 to a Freeview Recorder using a HDMI cable and mini-to-standard HDMI convertor (not included but not expensive) and dimming the room light levels and the c20 appears to have found a possible use. Probably not in an office but in a living room or more realistically a bedroom as a replacement for a flat panel TV.
With a flat, light coloured wall the images are clear and watchable without having to also acquire a projector screen. The HDMI feed from a HD device will give High Definition video quality up to 1080i. In my tests I mounted the projector onto a standard inexpensive camera tripod stand (<£10 from Lidl), fed a freeview HD signal from an AC-Ryan PVR and projected onto a flat wall 8ft away and achieved a watchable image with a diagonal image size of about 60”. The projector also comes with a built-in speaker and headphone/audio out socket.
The advantage of this over a TV or conventional protector is that is uses very little power (<10w), runs silently and gives you a 60” image for the same price as some much smaller TVs but takes up virtually no room.
On the down side I found that the projector did not run very long on battery so best to keep it on mains and you need to have a device such as a laptop or freeview/sky HD/DVD unit to feed it a signal as it has no built-in tuner.
I found the Acer c20 pico projector to be good, but maybe not for the original purpose intended. It takes very little time to setup, can be quickly focused using a manual focus wheel on the side although I did find that after the projector had been running for a while you had to refocus the image and the full image edge to edge/corner to corner – was not in full focus but to be fair I was probably pushing it at 8ft away and wasn’t too bothered that I was aiming exactly perpendicular to the wall.
Typical price is £160-180 online