If you're (last minute) after some Easter visuals for Good Friday and Easter Sunday, it's worth checking out ReelWorship. It's a free video and picture sharing website, and has some stunning pictures and lovely simple video loops.
And it's not just for Easter - there's also a great set of pictures suitable for using as backgrounds to powerpoint slides, and a range of abstract/themed videos. Some of the vids have background music linked in, so you have ready-made meditations. Full marks to Ian Britton, who set it up and has provided many of the resources.