hCard.XML is a free microformats hCard parser and reader and may be used on websites' About pages, or any place you might find suitable.
The hCard data (names, contact information, organization, address, etc) is stored in an easily editable xml file and is parsed with javascript into any webpage that contains certain css classes (determined as hCard css classes by http://microformats.org/) and is independed from the html it is parsed in (unless the used html elements have certain id's that are being looked for by hCard.XML parser).
Although hCard.XML is free to use, it's parser is not open source, i.e. the javascript is obfuscated and cannot be modified and edited. The free version also contains a credit line at the bottom of the hCard that cannot be removed or set to invisible.
However, the open source code is available upon purchase (100.00BGN, or their equivalent in Euro or American Dollar) and comes without the credit line.