Rosalind - 11:45 am on Oct 11, 2011 (gmt 0)

If by "not targeted" you mean irrelevant, then it's a wasted opportunity cost for little reward. Those irrelevant directories will be unlikely to list you, and those that do are likely to be the ones that add everything no matter how spammy or rubbish it is, and therefore pretty much valueless as a backlink. So there are pretty good reasons to stick to submitting within your niche or region.

The same quality control issue applies to some of the less well known general directories, and you can usually tell by going to the category page you'd expect to see your listing and checking whether the other listed sites are familiar competitors or near-random junk.