I got this recently as a birthday present and I was over the moon because I usually watch movies on my small iPhone screen at night when in bed (I can't use my TV because others are sleeping nearby) and I find my eyes straining. This unit is very small - palm sized which means it can fit in my pocket where ever I go and it comes with all the necessary cables to connect an iphone it it (although a built in dock would be cooler, neater and handier).
Now for the most important bit: the brightness! In the day time with blinds open it is basically unusable, i am going to be straight up about that.But this is not made for the day and at night it is more than bright enough to project a normal sized image on your ceiling. It can be battery powered but it lasts no time at all and the built in speakers are frankly awful but i use headphones anyway so that isn't a big factor for me.
Overall this is a fantastic bit of kit if you want to watch movies at night. Its a terrible bit of kit if you want to watch movies in the day! its up to your usage!