ok, first of all a disclaimer, i sell heart strings patterns.. so yes i sell the pattern i am about to brag on, but i only just found out about it. ...do not YET have it in stock, and i am not the only one who carries it.... you can buy it from me, but also right from the site or from your local yarn store....
Heart strings pattern for a deep front dickie:
http://www.heartstringsfiberarts.com/a8.shtm this pattern would be perfect for making a deep V neck or open front top into one suitable for more modest wear.. and ranges from fairly cool. to "ski wear" depending on the yarn you use to knit it with.
they have other dickie patterns (possibly some in crochet) including several that are lacy, or very manly, and others that are pretty generic and would differ depending on what yarn you used... most of the dickies would need to be made deeper in front to conceal a very low neckline, but the one i linked to is already longer in front (please note, except for the side to side knit one, it is very easy to lengthen the front of any of the patterns)