One thing I've been mildly-yet-obsessively entranced with for a number of years is how nicely Gawker plays with thumbnails:

One of the minor irritations of modern web design is that, even you HTML the hell out a blog post to make it look perfect in terms of graphical layout, by the time you trim, sanitize and otherwise disembowel that HTML for your teaser text, at best you'll have something dull, at worst you'll have something that wreaks havoc on the rest of your page. Gawker, however, automatically crops and resizes a photo as needed to create interesting, all-purpose graphic work that can be popped in wherever it pleases.
I was so jealous of the effect that I began working on my own Drupal module to copy it until I realize that, not only does such a module exist, but it's one of Drupal's most popular: ImageCache.