I'm a 'hoodie' rather than a 'filterer'
Not only do the lens hoods provide protection for stray light, (and I shoot a lot of back lit stuff, so this is important) but they also provide protection for the front element. The only filters I use are CP's or ND's. I also store all my lenses differently than most. All of my lenses are in third party soft cases, either the Adorama "Slinger" cases or the Lowepro ones. That being the case (pun intended) unless the hood self stores backwards on the lens like many of the bayonette ones do or retracts onto the body, all of my hoods are the rubber collapseable ones. as that way they fit into the case along with the lens. (I dislike having to screw on the hood every time I mount the lens) I've found they work great, and take up very little extra room. To the poster who complained about his lens cap not fitting with the hood, my answer to that is to get the caps that fit inside the filter ring rather than over it, that way the cap will clip right into the threads inside the rubber hood. I've also had no problem with vignetting. I use a "normal" rubber hood on my FA 20mm and have had no vignetting problems with it, and it provides better protection against stray light than the "wide" one does.
NaCl(cheap, do the job, and take up no space...what more do you want)H2O