RSS Submit is a nice small, yet very effective utility. You can load it with unlimited number of RSS feed URLs. Then, the program will enable you to submit them all or just the ones you choose to more than 130 online search engines and web directories.
The are two methods for submitting your feeds; the first method is the automatic submission. This one is suitable for most of the engines that the program supports, and it will work with just one mouse click. The second is the manual method; it will require you to go through certain verification processes on some search engines, such as captcha and email confirmation.
One of the greatest features of the program is that it can download and analyze your RSS feeds, and automatically extract all the keywords from them. It will finally submit these keywords, along with their corresponding RSS feed, so it can be well-indexed by search engines.
The program has very useful functions that depend on famous third-party providers; such as the feed validation service provided by "feedvalidator.org", and the feed traffic information provided by the free RSS service from "feedburner.com".
The only disadvantage I found is that you will need to buy the full version in order to be able to use all the search engines and directories that it supports.