What's the best way to accomplish this...?

[LD]

On my linklist, I have paysites and freesites mixed together with an icon and text telling the user the type of site. What I would like to do is allow the user to apply a filter and just get free sites, or just get premium sites..or just get blogs...etc but at least not appear to go to a different page.

I was looking at Wetplace, and they have a nice little tab across the top of the page, and it looks like they have built separate pages for both all sites in a category plus pages for each type of site within that category. Is that the best way to do it? You are actually taken to a different page, although it looks like you are in the same spot with different sites listed.

I use Dragon, and I can do a php call which pulls up the selected criteria using a link, but it's not exactly what I want since the sites do not look like they are part of the design. I want it to look like the user has not left the page, but merely applied a filter.