better "go to file" matching?

Currently if I want to open something.rb

typing "some rb" does not show "something.rb"

I have to type "some*rb"
it would be nice if "some rb" also matches "something.rb"

also if there is no file that start with "something", it would be nice to list files that match "something" anywhere

for example typing "some", shows "not_something.js", "_something.rb"

I think this is how sublime text and textmate does the matching.