The following User stylesheet snippet can be used to highlight particular search results (such as your own domain, if you want to quickly find it in Google search results):

@-moz-document url-prefix(http://www.google.com/search)
{
a[href^='http://www.vitavonni.de/'] { background-color: yellow; }
}

You might also want to add a copy for your localized Google domain:

@-moz-document url-prefix(http://www.google.de/search)
{
a[href^='http://www.vitavonni.de/'] { background-color: yellow; }
}

Or you could go the heavyweight way:

a[href*=vitavonni.de] { background-color: yellow !important; }

to even highlight any link to your domain.

This modification obviously only applies to your browser; it’s meant to help you finding links to your own site more easily.