I recently switched to BibLaTeX and also convinced Michael. Key advantages are: a huge supply of entry types and fields, comprehensive customizability, better Unicode awareness, and an exhaustive documentation. Among the best features is that one can now properly cite URLs. Not only is the url field supported (and displayed!) for almost all entry types, but also there is a standard way of saying when you last visited a URL – either a combination of the fields urlyear, urlmonth and urlday, or alternatively urldate = {YYYY-MM-DD}. The only tedium that remains is entering such dates. Users who, like me, use the AUCTeX Emacs mode for editing LaTeX and BibTeX, might find the following macro helpful. It is ready to be used in your ~/.emacs file:
(defun bibtex-insert-current-urldate ()
(interactive)
(bibtex-make-field
'("urldate" "" (lambda () (format-time-string "%Y-%m-%d" (current-time))))
t))
The following line binds it to the keyboard shortcut C-c u:
(add-hook 'bibtex-mode-hook '(lambda () (define-key bibtex-mode-map [(control c) ?u] 'bibtex-insert-current-urldate)))
With the default BibLaTeX style, the urldate field will render as (visited on MM/DD/YYYY).