Ever since I knit my first cardigan, I have disliked sewing up seams and have never really been happy with the results. I think part of the problem is that I am so impatient to finish, I tend to rush the seams. When I learned about seamless knitting, I knit a few seamless cardigans with better results.
When I learned to crochet, I was surprised to find few seamless patterns. Crocheted seams tend to be rather bulky and crochet lends itself well to seamless and modular designs. I recently started a Seamless Crochet group on Ravelry. I was initially a bit worried that nobody would join, but so far we have 20+ members.
On the subject of seamless crochet, I have just bought Everyday Crochet by Doris Chan (seen here with the Winter Issue of Interweave knits).
This is probably my favourite crochet pattern book so far. There are several top-down seamless garments (tank tops, long sleeved tops, cardigans, jackets) with a number of size and design options, as well as some nice crocheted belt patterns. I often end up selling my pattern books once I have browsed through them, but this is definately one to keep.