I was introduced to Buffer today, and I'm quite pleased. This free service, simply put, buffers your tweets and/or Facebook posts until issuing them according to your predetermined schedule. The default Buffer size is 11 entries, which is more than enough for those "post them whenever" kind of links that curators of online content always seem to accumulate.
The key piece of the Buffer puzzle, for me, is its Firefox plugin. It's fast and clean, and it makes it ridiculously easy to stash a tweet/post in one's Buffer while surfing the Web. When you read as much as I do--and from as many sites--this quick-and-easy approach makes all the difference. Instead of flipping from browser to Twitter client, I simply stock up my tweets as I'm reading; you just can't beat that kind of ease-of-use. The fact that it's provided as a Firefox plugin gives you cross-platform availability out of the box.
Seriously, check it out; this one's a keeper. (Full disclosure: if you sign up from the link below, we'll both get an extra entry added to our Buffer...)