I can't tell you the number of times I've had an interviewer come into the room and clearly state that they haven't even read my resume yet (so excuse them if they take a minute to look at it first), much less looked up my projects or my website. This has happened everywhere, from tiny startups and Google/Microsoft/Facebook to banks and contract positions. Even when I've worked on projects related to the company (e.g., Twitter and Facebook apps when I interviewed at them), the interviewers had no clue (and I mentioned them quite prominently on my cover letter/resume/site). They don't look them up afterwards, either (using Google Analytics, I can tell whether they've visited).
There have been a couple times when the interviewer has looked up and liked my projects, and we've had fun discussing them, but this has been quite rare.
So unless you're directly using your projects to market yourself (i.e., you're purposely using them to network, rather than just doing them for fun and "passion"), I find this advice rather naive.
But maybe I'm just Doing It Wrong, and YMMV.