I'd think palm rolling would be your best bet...and I've see Beksta say that you can turn the ends up on themselves and put lil rubber bands over them to encourage them to round off at the ends...not a very good description...hopefully she'll come around and give a better one...

i am experiencing the same thing. my dreads are on the thin side and therefore the ends are wispy. i like wispy ends just not as long as they are. because they are small i know it will take loger for the ends to lock up. how can i speed this up ? i want to keep the ends wispy (just shorter) as i dont like the look of rounded ends.

Yep yep, get yourself a wool or tapestry needle...these are the ones that are thicker and longer than regular sewing needles, with bigger eyes for threading. Insert the pointy end of the needle up into your dreadlock, through the middle, from the very end, and poke the pointy end back out an inch or two up from the tip. At this stage you should have both ends of the needle poking-out of your dread, but the middle threaded-up through it. Now take the wispy bits (you can even do this with more hair, as long as you divide it up into smaller sections, for ease of threading), twist them between your fingers to make one 'strand', and double it over...thread it through the eye of your needle and pull it tight through the eye. Now grab the pointy end of your needle and pull it through the dreadlock...this will pull those wispy tips up inside your dread and create a rounded tip. If you have any difficulty pulling the wispies up, I often use a pair of nail clippers to grab the needle to pull through, for extra grip and strength...but generally this is not needed....only when I've made the mistake of pulling too much hair up in one go.

Good luck, this method works great!