Moblog is a blend of the words mobile and weblog. A mobile weblog, or moblog, consists of content posted to the Internet from a mobile or portable device, such as a cellular phone or PDA. Moblogs generally involve technology which allows publishing from a mobile device.
The concept is great: update your blog when you are on the go.
As a good example of moblog, please visit Loic Lemeur's "Daily Views"!