Some interesting sites bloggers or blog readers may be interested in:
You guessed it, it kind of works based on del.icio.us. Particularly interesting for avid blog readers who like to be directed to other blog sites, but do not want to do so quite as randomly as hitting the "next blog" button at the top of blogspot sites.
It's basically a search engine whereby you type in the url of a particular blogsite, and then according to the maker, "it answers the question 'people who tagged this site also tagged what other sites'".
Pretty interesting stuff. Fair warning though, do not expect the search results to show you other blogsites that have similar content as the one you typed in. People have interests in a whole variety of topics after all.
This one I'm particularly interested in, although I haven't actually submitted anything to them yet. What it basically does is allow you to send in content to be reviewed by the community, who will vote on it and let you know just how interesting they think it is.
Alternatively, if your ego is too frail for that kind of beating, you can just read what others are submitting.
Probably more relevant to bloggers who have a huge fan base, are making bucketloads from their site or looking to further promote their site in a more corporate way (read: not me).
It's basically an email marketing tool whereby you can send out promotional emails or email newsletters with a daily, weekly or monthly summary of your blog to a particular mailing list.
[Thanks to Steve Rubel for the links.]