As I stated in a previous comment, it's called "incremental search" and you can do it in vim. Look here for how: http://linuxcommando.blogspot.com/2008/06/smart-case-insensi...
yea but unfortunately it's not that good ... think it's better than default search but a still too slow as a mean for code navigation (atleast for my taste). it's mainly due to needing to hit enter, which escapes everything, there should be a way to hit next occurrence and prev without leaving the /search box.
n for next match, N for previous match.
In combination with this it's almost as effective. Personally I'd use ctags and the http://vimdoc.sourceforge.net/htmldoc/tagsrch.html#tag-comma... search functionality of the tags. But I'll give you that normal text searching in emacs is a tiny bit more efficient :)
anyhow, i don't use vim anymore but when i do, i'll give it a shot. i know i can't live without seeking, it's such an important part of your arsenal.