Apologies if this has already been mentioned, but a new website called Evidentree is beginning to take shape as a place where family historians can find out each others surname and place interests by uploading their GEDCOM files. You can also set up your own groups if there is a particular area of interest that you want to share with others. It is still very early days for this website so there aren't that many members yet but if we spread the word perhaps it could become a very useful resource in the future.