An excellent discussion to start. I'm in this exact dillema right now. I go to client meetings and I've recently been asked a lot more often to see my work in person. Up until now, my website has been sufficient, but I'm wanting to show something in person and I want to see their reactions to my images. (Obviously, I don't have an actual studio, so a large screen TV or projector isn't an option at this point...although optimal)
With the iPad 3 coming out within the next week (retina display for hi-res, crisp images) it's looking like a VERY good investment. I wasn't happy with the iPad 1&2's displays because they looked like what can be found on the web anywhere. Good, but not as good as print.
So now the issue becomes, spend the money on a printed portfolio that needs to be updated/reprinted at regular intervals (smaller chunks of $$, but more often) or get the iPad 3 and have the ability to update/change portfolio pictures at will (bigger upfront cost, maybe offsets the ease of use and pays for it self over time?)
I'm strongly leaning toward the iPad 3 because it can be used for a myriad of other tasks as well, thus further off setting the cost. (Contracts in .PDF form, website/in-person ordering, and personal use of the iPad)
Those are my thoughts, and I haven't settled on one just yet, so I'd like to see where this goes.