http://www.nearby.org.uk/opensearch/

… includes a Gmap to make defining the lat/long and/or bbox easy. (if the file has geo extensions)

(Just submit the same file again, if you update it. btw don’t submit a definition file you don’t want to become public, but remember it is called ‘open’

I realised after mentioning we updated the description file on www.geograph.org.uk, that it wasn’t fully tested, (hate testing, but not adverse to spending 2 hours scripting a tester), and in fact this tool highlighted a mistake!

Hope it of interest, feedback welcome,

Naturally I couldn’t not add it to the Geograph OpenSearch definition, will have to keep an eye on the logs to see if there is any take up…

This also reminds me that nearby.org.uk is in need of some loving, there are some datasets locked away within that could be made searchable (of course geographically!) in this way.
One thing that struck me reading the proposal, is that a method to specify geographical extents that the engine works with. Thereby a sane search initiator could know that searching Geograph for locations in Austrialia is likely to end in tears….

Something like a simple:

<opensearchgeo:extents>
<georss:box>49,- 9.5,62,2.3</georss:box>
</opensearchgeo:extents>

Would probably do it

Update: Sorry, just relised the tags didnt show up, seems TinyMce inside wordpress, decodes entities on its own, so double(!) encoding it is then.