Illuminated Manuscripts are cool.

I was searching around for some (I like to use stuff like this as the background on my portrait-oriented monitor) and happened across the British Library's Digital Catalogue of Illuminated Manuscripts.

For instance, they've got some cool images from the Lindisfarne Gospels, like this image of St. John.

The easiest way I've found to browse the collections is to just go to the Manuscript Search page and use the drop-down to select a collection ("Cotton MS" for Lindisfarne) and leave the "MS Number" field blank. Then hit "Search".

Enjoy!