Regifting is very likely here to stay. But the question remains...
Is It Ok Regift? (Meaning to give a gift you've received to someone else.)
Not really. Regifting is a symptom of the surplus of "stuff" many people find themselves with, and their desire to be practical and give away things that they know they will never use. Still, gifts should be recycled only rarely, and only under the following circumstances:
Simply put, you have to make sure you don't hurt anyone's feelings—either the original giver's or the new recipient's. Would the person who gave you the gift mind that you passed it along? Do he and the recipient of your gift know each other, and would it be awkward if they realized that you've regifted a gift from one to the other?
What's Wrong with Regifting?
As mentioned above, it can hurt feelings if it's discovered. It's inherently deceitful, and good etiquette is about not only being respectful and considerate, but also honest. Honest in this case means being authentic and genuine, as well as not telling a partial truth. When you wrap a present and give as though you bought it yourself it says, "I got this for you," while leaving out the rest, "...from someone else who gave it to me," which, if the recipient did know, would likely be interpreted as lazy or short on thoughtfulness or effort on your part.
That said, there are times when it's okay, as in the following two examples. The first case is about practicality—you really might have bought this item, but you just happened to have an extra new one on hand already. Though frankly, the second is really the best way, because it's completely transparent—more of a thoughtful pass-along than an attempt to pretend you went out and shopped for this item with the recipient in mind.
Only you can decide whether a scenario meets the criteria above. Think through each situation carefully, and if you're still in doubt, don't do it. Saving on the time or expense of shopping for or making a gift isn't worth the cost of hurt feeling or a damaged friendship.