Form in CI: POST and GET

[eluser]developer10[/eluser]
Im rebuilding my site using CI and sooner or later i will have to rebuild basic search form

current live site (link in my signature) shows you how that looks. only 2 fields:
category and city.

if i use GET, i will end up having "?company=Something&city=Somecity"
and im not using querystrings in my CI development

i want my form after submitting to get me somewhere like this:
"mysite.com/index.php/show/company/city"

how do i accomplish that?

is using POST solution?

if i wasnt clear enough, just ask and i'll try to be more specific!

thanks in advance