Fruitcake you may be, nutty you're not - they're *really* good. Particularly Urban Portraits.
Not that much Google Juice for that as a phrase, but it's taken as a domain name - singular and pleural. I think I'd want the domain names if I was using a two word strapline. Now,
www.cityportraits.com is taken, but it's not being used (it's up for sale in the USA) and the domain's free as a .co.uk.
www.urbanportraiture.com, on the other hand, is free
Urban Portraiture? I appreciate that portraits has a wider connotation, but you can have
portraiture of a place as well as person, no?