[thelist] Custom Error404 redirect

[Daniel Fascia]

Is using a custom Error 404 page to make cleaner URLs a good or bad idea?

Currently Ive set up my page so that index.html is the error 404 document and it has a piece
of PHP which parses the REQUEST_URI variable and works out what content is needed
in the page from that...

it works like a dream but Im just concerned that this is a bad way of doing things in terms
of offending googlebot and others. Will he spider the site or will he just think its always returning
an Error 404 each time a page is requested?