does it make sense to submit to any of the smaller, less heard of search engines? if so, which search engines would you suggest submitting too and where can i submit to them?
It does and here is a list of 189 search engine submission pages. http://forums.digitalpoint.com/showthread.php?t=755774
You are correct, but it does not hurt and you never know when you might get a bit of additional traffic from the smaller engines. It only takes a small amount of time to submit to have a permanent listing in their index and possibly get some traffic in the future.
I also think it is well worth submitting to as many search engines as possible, why not?. I do believe that the majority of traffic will come from google but you never know, you may get some important traffic coming from the smaller one's, as you will be aware the more traffic the better.
Even if you don't get too much traffic; you know that for the small percentage of people who use it you have a chance. Better than nothing, anyway.
You could spend your time doing more useful things then submitting to "little engines" that will generate you virtually no traffic.