Solo brunch ideas?
I don't see why you can't go to Balthazar solo unless you are averse to sitting at a table by yourself. (I don't recall seeing any bar seating.)
Balthazar photos: http://www.flickr.com/photos/11863391@N03/sets/72157621977198042/
Bar Boulud would be a very good choice for solo brunching. They have bar seating -- it's a long table -- as well as the circular "tasting" table. My husband and I sat at that circular table when we had brunch there last year.
Bar Boulud photos: http://www.flickr.com/photos/11863391@N03/sets/72157616424232698/
Haven't been to Perry St., but we've enjoyed Nougatine, the casual Jean Georges restaurant, which has bar seating and would a good brunch option.
Nougatine photos: http://www.flickr.com/photos/11863391@N03/sets/72157622090066758/
Edited to add: I see kathryn has come to the rescue re: Balthazar. So, there is bar seating.
One more suggestion: Maialino, which has bar seating.
Maialino photos: http://www.flickr.com/photos/11863391@N03/sets/72157623134601069/