I've been looking to buy a new monitor and was wondering do I really need one with a HDMI input. I won't be playing PS3/Xbox or watching Bluray DVDs on this monitor. Is a HDMI input useful for anything else besides that?
You get the same picture with HDMI as you would with DVI. The ONLY advantage to HDMI is it can carry digital audio as well as video. So no, you don't need HDMI. It isn't any better then DVI.
For the added versatility I would opt for a monitor with DVI and HDMI.
Just for the fact if you wanted or needed to plug a DVD player or something into it, you could.
Price wise, there isn't a whole lot of difference, so Meh.
HDMI "future proofs" your display but if you're sure you won't be connecting to game consoles or Blu-Ray players then DVI should be enough. Should you need to updated your hardware, there should be plenty of graphics cards supporting DVI for years to come.
One thing not really touched on is a digital signal is a digital signal... This also goes for cables carrying the digital signal. The only difference I am aware of is shielding in the cable to help prevent interference, but other than that one will not produce a better signal than the other. HDMI is the way of the future for now, and as others already said you can have audio over HDMI to save you from running an extra audio cable if applicable. Hope this helps.