Has anyone here found the need for the hood? it seems kind of useless... is there a hood from another lens that might work/function here?
And how about a carrying/protective case? Do most of you just stick this in your bag, or is there a need for some kind of pearstone/case etc?
No point in the hood, at all. I worked out the geometry some time back, and the dedicated hood for the 40/2.8 doesn't actually provide any optical benefit, from what I can tell. It's too shallow to protect even a 14mm prime from flare. Since it screws onto the extending front element, 'protection' is questionable, too.
The ES-62 hood (for the 50/1.
with it's 52mm threaded adapter will fit on the 40/2.8. It's much deeper, and reportedly doesn't vignette, but would likely provide some flare protection.
The 40/2.8 fits nicely in a Lowepro 8x6 case, but I just put it in my bag or more often, my pocket.