Recently launched, minimalistic, and highly focused:
BrainStorm [brainstorm.naviance.com] is an interesting tool written in Rails for web based collaboration. You can create Conversations and invite others to participate. It’s still a little bit buggy but quite interesting, since you can add a variety of content fragments – appointments, checklists, ideas, quotes, reminders, tasks, and so on:
Pixoh [pixoh.com] is an online photo editor. Currently it lets you resize, crop and rotate photos, but more features are on the roll.
ShortText [shorttext.com] lets you publish microchunks of text on the web. Each fragment gets its own (short) URL. Nice.
Last not least FeedSifter [feedsifter.com] lets you create filtered feeds which only let pass items containing specified keywords. This is handy if you want to scan many feeds for specific topics only.