Have you discovered Pinterest yet?
If you haven't, then go take a peek. For a while now I've been on the look out for a way of bookmarking images. Tumblr didn't appeal to me as it seemed too similar to blogging. What I wanted was something more like an online scrapbook. Pinterest is still in it's beta phase, so to join, you send a request and wait for an email (which only takes a couple of days or so). Once in, you create pinboards to collect images on, here's one of mine...
The 'designer aware of copyright' in me does have to admit to feeling slightly bad when pinning images as it is kind of taking without asking, but I have been making sure to credit the correct people or artist by labeling the images. That way it keeps it more as a way of sharing inspiration than pinching ideas, ie I reckon it's ok, as long as you play nice.
As with most online communities these days, it's all about networking, so on Pinterest, you can follow others and keep up to date with what they are pinning. Here's me if you fancy joining in!