I was at Gabriel Brothers last week (I totally shop there), and came across some dresses that had been marked down to $3(!). Loved the print and soft jersey material, but the bodice (as in, the top part) was totally not working for me - it had a really weird cut and was not flattering at all.
So, I went for the cheap, cheerful, and doable-by-anyone-with-thumbs option: I bought 2, took them home and cut the bottom off just above the drawstring. And that's it.
And now I have 2 cute skirts that are a good length, comfortable and match a lot of stuff. I didn't even have to break out the sewing machine, since jersey doesn't fray.
Did I mention this was quick? As in, I had nothing to wear for church, remembered the dress waiting for me, hacked the bottom off with my rotary cutter and put it on. I suppose if you're using scissors it may take a little more time - about 90 seconds, perhaps. Surely you can hide from your children for that long before they find you...
Might I suggest you check a local clearance rack for some conversion material of your own? If you find prices like I did, it'll be totally worth it!