If you're only intent is to show images to friends, then the iPad is pretty nifty (even the Photos app has a good slideshow function), or any number of digital options up to using on line facilities like Flickr on your television. Regrettably (perhaps), this is how most people show and exhibit their work these days. It is expected to be at least a part of your repertoire, no matter the audience.
Showing actual prints unpresented, is a sure sign of your amateurism, in its most vulgar sense. Nothing looks worse than bare, warped prints, a problem magnified by appparent contradictory "professional" use of fiber based papers. Your commitment to your art and its medium is evidenced by your desire and proficiency at setting the stage properly for your work. I strongly suggest you mount them (or have them mounted) for presentation (windows not being necessary for portfolio use), where they may be handled safely by others through proper support, and given the respect they deserve by any viewer – friend, gallery owner, or even better, both.