Hi, MtnMan.
Years ago I bought a set of Faber-Castell dry Textliners from Levenger. They are excellent—fluorescent in brightness and mostly erasable. They came with a sharpener (they're a little fatter than regular pencils), or you could sharpen them with a knife. They never dry out, because they're dry to start with. I liked not having to worry about capping them.
Levenger no longer sells them. They have their own product (
HTTP://www.levenger.com/PAGETEMPLATE...2-3|PageID=165), which is a refill that fits in a rather pricey holder. You could order the refills and mod them with a pencil grip.
For some reason, the Faber-Castell product seems not to be for sale in the U.S. Here is their current version (
http://www.penciltalk.org/2009/05/fa...ighting-pencil)—cute! The page has a picture of the version I have. Products by other manufacturers, such as Staedtler, draw less favorable reviews.
This site (
http://givegoodgift.ca/?p=1561), in Canada, came up in a search; the page is as recent as last August, but there's no buying information. She gives an email address, so you could ask her what's up. Very reasonably priced.
Meanwhile, Levenger has this page (
http://www.levenger.com/PAGETEMPLATE...-3|pageid=6403), but I don't know if it's a current offering; it didn't come up in a site-specific search for highlighters. You could call them. The price is even better, but I don't have personal experience with them or the refills above.
It's not a silly question at all. This is a really useful product.