Geograph - photograph every grid square

If you know your current password, just login as normal view your Profile, and click the 'Edit your profile' link.

If you don't remember your password, use the 'Forgotten Password' facility, to change your password. You will need the original email address you signed up with.

If you don't remember or are unable to access the email you have setup on your account, then you will need to use the Contact Us link to get help from a volunteer Team Member.

It's essentially the most viewed - weighted so length the image been on the site is taken into account and deduplicated so only one from any shots taken same day. The alternative selection is different, in that it carves the period up into a number of periods (by submission date!) and then just displays the most viewed in that period. For more info see forum thread.

You can submit all your photos under a pseudonym by changing the name on your Profile http://www.geograph.org.uk/profile.php (link top write on most pages). Note that by doing this, the name will be changed on all photos you have previously submitted from the account. These may already have been used elsewhere, crediting the name originally shown.
You can change the credit on an individual image, for instance if you asked someone else to take it for you, but the name on your profile will still be shown on the photo page and the photographer name will still link back to your profile.
You can open another account under a pseudonym but this will need to be done from a different email address and you will have to take care which account you are signed in with before submitting, making changes or posting in the forums.

Accounts cannot be deleted - see this answer http://www.geograph.ie/faq3.php#103

If you have submitted no photos the only way anyone can find your account is by trawling through every account number - in November 2015 there are around 122100 of them.
If you are still concerned about your name or email address being available you can edit your profile to anonymise your name and introduce an error into your email address (which is not visible unless you have set it to be so).

Short answer: you can't. But please read on...

You can't revoke the Creative Commons licence you have given The World when submitting your photos, and we would like to ensure as best as we can that you continue to get credit for your images wherever they are used. If you stop submitting, your existing photos remain visible and credited to yourself for this reason.

If you would prefer no longer to be identified as the photographer of the photos you have uploaded, you can change your real name in your profile http://www.geograph.org.uk/profile.php?edit=1 to show a pseudonym, or you can ask us http://www.geograph.org.uk/contact.php to anonymise your account. In either case, your decision is reversible should you change your mind - which of course we do hope!

If your friend asks you to and for some reason cannot create their own account then that's fine provided they understand the Creative Commons licence. You should credit them as the photographer when submitting.
See related article: Photos not taken by submitter