The Wellcome Library has a quite lovely blog. I like their 'item of the month', the way they're addressing common questions 'where do things come from', the list of latest aquisitions (though it's about as human readable as I feared it might be), a 'call for testing' when they've got newly digitised records up... it's a good example of transparency and the provision of access in practice. It feels a little as if you had a friend who worked there who sent on little tidbits they came across during the work.
The site says it has (the uber-annoying) Snap Shots but it didn't seem to actually be interfering with my browsing experience when I checked it out today.
There's a Flickr stream too (though they haven't yet nabbed a name, so it's at the not-so-snappy http://www.flickr.com/photos/26127598@N04/) and it hasn't been updated since what looks like a big batch upload in May 2008. Some of the images are lovely, check out the human cancer cells, or neurons in the brain or historically important - such as the first DNA fingerprint.
They've just added Charles Babbage, I wonder if they have anything on Ada Lovelace they could highlight for Ada Lovelace Day.