private feed/profile with user defined guest access

is it possibl to have a private blog focussed around a user profile and perhaps their activity feed which was private from other users (so not community as such) and were able to assign a guest pass either with once only access or have a gust user for their proile which they could change the password for.

looking at mulsti site, buddypress, communities and members and cant quite see a way

any ideas?