I'm sure many of you have already read this article at some point, but I figure its of note. It talks about an alternative to the ls/vtec that just so happens to be a super-high reving NA monster:
http://www.hstuners.com/news/wmview.php?ArtID=33
Also take note of the article before it; a good read, but not very relavant to people who aren't obsessed with high revs or are looking to go FI.
: stronger internals and workin toward that 1.75 R/S ratio are another 2 really good ways to increase rev limeted
x2: a lot of the gains from a high reving engine can be seen on the track because when you shift, you will come into the next year at a a higher rpm and therefor, hopefully, at higher power. Keeping the car close to the 'sweet spot'.