Many seo's will tell you that submitting your site to a search engine more than once is considered spamming. I've also been told by seo's that submitting to dmoz more than once is like being in a really long queue, leaving the queue, and re-entering it at the back!
If I submit at all (its not usually necessary, the way google and yahoo are going at the moment, as long as you have links to your site you will be crawled) I only submit once and that does the trick.
I suggest you check with some seo's though.
Search Engine Optimization is almost a myth. The most that you can do is make a site that people are willing to visit on a weekly if not daily basis. That has to do with content. As far as DMOZ is concerned, they take a long time to add your site because they are picky about who they add to their engine. That is why their engine is one of the best out there. Yahoo Directory charges an arm and a leg to submit. Overall be concerned with your content more than anything, the bots will come.
[quote=hysteriaweb]Search Engine Optimization is almost a myth. QUOTE]
I have no idea what that sentence means and why its ALMOST a myth.
If you are already listed then work on content, etc. If you want it spidered more, than get as many links to your site as possible. I submitted once when I first built my site but it wasn't until I had the backlinks that I started to see massive (and deep) spider traffic.
I find that if google say accepts your site then you will be fine adding tage revisit after 2 days etc and if you have new content that cant wait for another month then submit it to google. google is given as an example.