Contiguous sleeves are seamless, but look seamed. I love them! Rav member SusieM invented the method, and there's a group on Ravelry with more information on how to complete the sleeve.
Here's a WIP photo of the shoulder:
The bottom of the sweater is still above my natural waistline, so I have quite a way to go before I can start on the dreaded sleeves and hood. I hate doing sleeves! I actually have a sweater that is all but done, thanks to the sleeves.