Donna Karan New York posts up to four times a day about what's going on in New York City. Its a great way to keep up with all the (mostly) fashion related things going on you wouln't have otherwise known about. Even if you don't live in the city, at least you'll know where some of your masthead friends are socializing.
To be honest, I don't really know exactly what the theme of this blog is about but its run by LVMH so lets be honest, its amazing. Similar to the DKYN blog its got current fashion and art world type things posted. There get great access through there connections that not many other blogs can compare too - especially in the semi-competitive cycle. I've spent at least 10 hours trolling this site in all - the archives deserve notice.