Depends on the ISP, and, moreover, it depends on the granularity of  information they provide.  Most ADSL ISPs seem to enjoy churning IP addresses every 24 hours (possibly small hours resets of their exchange equipment).  Many geo-attempts I've seem simply use ISP's  registered addresses (hence eveyone lived in Woking, at one point).  Smart reading of the traceroute will often give almost street level location but I doubt many people do that.  I know little about geo-targeting,  but it is something I need ot find out about, so any useful resoruces....

On 16/05/2011 14:52, Deryck Chan wrote:

Chris,
Currently geo-targeting is only accurate to country level (due to ISPs randomly moving IPs around within a country - Magnus, is that correct?), so the only surefire way of targeting all of Cambridge is to scoop up all of the UK, unfortunately.
Deryck

On May 16, 2011 2:05 PM, "Chris Keating" <chriskeatingwiki@gmail.com> wrote:
> Can I suggest some rather tighter geotargeting for that notice - at the
> moment it appears to aim at every Wikipedian in a box with Belfast and
> Calais as its opposite corners....
>
> On Mon, May 16, 2011 at 8:55 AM, Michael Peel <michael.peel@wikimedia.org.uk
>> wrote:
>
>>
>> On 16 May 2011, at 08:48, Charles Matthews wrote:
>>
>> > On 09/05/2011 11:05, I wrote:
>> >> I have posted a page for the next Cambridge meetup:
>> >>
>> >> http://meta.wikimedia.org/wiki/Meetup/Cambridge/11
>> >
>> > A site notice for this event would be helpful.
>>
>> I've set up an en.wp geonotice for it (which appears at the top of
>> watchlists). In general, the place to request these is at:
>> http://en.wikipedia.org/wiki/Wikipedia:Geonotice
>> and any admin can make them live, by editing the page at:
>> http://en.wikipedia.org/wiki/MediaWiki:Geonotice.js
>>
>> Thanks,
>> Mike
>>
>>
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>> wikimediauk-l@wikimedia.org
>> http://mail.wikimedia.org/mailman/listinfo/wikimediauk-l
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>>

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