I just got an invite from Mike Speiser, Yahoo?? VP of community, to join its newest social network, called Mash. Actually, he created a profile for me, illustrating an interesting wrinkle on this latest of too many social networks: Other people can add stuff to your profile. Frankly, the service, in invite-only beta for now, seems aimed at people a tad younger than I. I?? also suffering from social-network overload, and I?? sure I?? not alone in that. I probably still have room for one or two others, but since I??e got Facebook for a general-purpose network and LinkedIn for strictly professional stuff, I think only if they??e really focused on small, discrete groups will I add more. I?? not yet sure if Mash will be it, as it inevitably evolves, and I have to put it through the paces to determine if Yahoo has latched onto something this time after its misfire with Yahoo 360. But at least Yahoo isn?? giving up on the Web?? most compelling application today, which counts for something.