there is a reason for this. Prezi is a zooming presentation platform; it literally zooms in and fills the screen with whatever you click on or tell it to look at. So if you've got a little 10px by 10px picture, it's going to be shown far, far bigger than is ideal when Prezi zooms right in on it -- hence it'll look grainy. When, for example, taking a screen grab you want to feature as an image, don't crop the screen-grab down to the bare-minimum -- try and leave enough of an image so Prezi doesn't have to focus in too close.This is hard to explain, do you get what I mean by this? Basically, anything smaller than what fills your screen in its original context, may look a bit shonky on Prezi when it is enlarged to fill your screen in a Prezi context -- just like if you zoom in on any picture and start to see the pixels, or just shove your face really close to a newspaper. This issue is exacerbated when your presentation fills a big-screen at a conference venue. So, no tiny pics, okay? Specifics: Moving a bunch of stuff at once with the Shift key, creating proper hyperlinks by duplicating, using frames, and embedding youtube vids. Often you can spend ages assembling a little cluster of materials, only to find they need to be moved -- and if you select one you can move it, but then you have to go back