On more than one occasion I have purchased a dress thinking, "It's not THAT short" only to later regret it. There isn't much fun derived from constantly shimmying your dress closer to your knees. It's just awkward.
With my mistakes in the past I've been able to remedy that problem for others. Last winter I added a strip of fabric to a maternity dress, it looked perfect and I felt so much better. My cousin, Caitlin, bought a really cute dress but didn't feel comfortable wearing it due to the length. I'll add that she has legs for days which just emphasized the short length. The dress was made from a medium weight brocade. I found a suitable piece of fabric in the home decor section.
Due to the flare of the skirt, I patterned the extension in wedge shapes. It took a little longer but I think it was worth it!