Thanks Rupert. That's a useful link and there are some impressive
gardens in there ... certainly will keep that as a site to re-visit.

It is close to what I was thinking of, but I think that unless I
visited it every day, and checked every folder, I'd miss new images
because they're so hidden away in individual sections.

I quite like the way flickr (for example) chronologically sorts images
so you can see the latest additions to the pool, and the way people are
able to comment on images or make suggestions. I appreciate that I'm
only thinking in a 'flickr-like' way because that's what I've got used
to - I'm sure there must be other gardening image based groups, equally
as interactive out there.

Anyway, I browsed around flickr a bit more and came up with these two
group examples to show what I mean... I'm going to keep looking for a
group where informal images of ordinary UK gardens are pooled and
discussed - but haven't found one yet.

English Gardens: http://www.flickr.com/groups/englishgardens/
Allotments UK: http://www.flickr.com/groups/10369993@N00/