I am the sole owner and webmaster of my site. That would seem to suggest that the singular (I, my, mine, etc.) would be the most descriptive and honest usage. However, I choose to use the plural (we, our, us...) for this reason: although most of the inner pages are my own content, I have (with permission) included a limited amount of content that is not my own. Therefore I do not hesitate to use the "we", even though I am the sole owner and webmaster.
If you own a company or work with somebody else then you can say "We". A lot of people use "We" on their personal web sites to make it look more professional and to give out false impression that their site is so important that it requires a team to run it. Personally I use "I" because I run web sites on my own.
If you have multiple personality disorder you can say i work for the directory, and so do i, we all do, and have different voices for each, and not strictly be telling any lies either. You could sack yourself and still be working for the directory, you can also stop your own wages and still be getting paid. Ah the joys of multiple personality disorder.
Most of my project I'm using "we". It's look more professional and you got a team even you work alone.