I use both my smart phone and an ipad if necessary. In the showroom, I have a 32" wall mounted monitor that loops through 666 photos of my work from over the years. But typically, I rarely have to show a portfolio as most have already visited my website and looked over my work before making contact.
It's not so much about how you present your work, but how good your work really is. A dozen fantastic incredible photos are 100 times better than hundreds of mediocre pictures of letters stuck on a board. If you're going to show it, make sure it's your best work possible.
