tagging using signature messsages coms up with an error
the only way that currently works is to have your website show a page that mentions your bitcoin address. and then in blockchain.info us the ''website link" verification
https://blockchain.info/tags?form_type=1where you type in your bitcoin address
write the tag you want to appear
paste your website page that lists the same bitcoin address
do the captcha
..
most people make a website page that simply says "hey folks this is my donation address: " <insert bitcoin address>