Psykopaint is really fun, visually interesting and free. It is a rich internet application in which you can turn your pictures into paintings by grabbing one of the 6 brushes provided and start painting while the colors are selected automatically for you. Created by Mathieu Gosselin.
The Third View project is a fascinating presentation of "rephotographs" of over 100 historic landscape sites in the American West that presents original 19th-century survey photographs, photographed again in the 1970s, then once again in the '90s - from the original vantage points, under similar lighting conditions, at (roughly) the same time of day and year. [Flash, and you'll probably need to allow pop-ups; a little more info inside...]
Two completely dissimilar yet nifty artists: The twisted ink drawings of Jon Kuta (big enough to make desktops; Flash interface), and the fabulously lifelike driftwood and bronze sculptures of Heather Jansch (she really likes horses. Warning: you'll have to side-scroll).
How To Have A Ton Of Fun Raising Baby Squirrels. Husband and wife document their adventures raising these little spazz-monsters with many photos and some Flash movies. Via Cute Overload.
A flashy website ... but the photos are beautiful, especially the portraits. Some look as if they could have come straight from the pages of 'Life' magazine c.1935. Note: A couple of pics are NSFW
Slightly ominous, slightly beautiful collection of ePostcards (and photographs) of Streatham Cemetery, rendered in the subtlest use of Flash I've ever seen (gentle animations on small portions of each image. Be sure to view the cemetery in all four seasons, multiple pix of each.