I've used khuana before and its a nice interface to help speed up commenting a little bit but the software doesn't allow you to comfirm that site is still dofollow. ie- using firefox and the nodofollow plugin. After using the program for a few days I checked the sites in firefox and I found I wasted a lot of time since about 50% of the sites are actually NOfollow. But this is pretty standard with most dofollow tools.
fastblogfinder is another good tool that can help you find dofollow blogs and manage commenting. IMHO, you should be commenting 'manually' and use software ONLY to find relevant blogs.
true. Reason being, at the moment there is no commercially available autocommenter that is sufficiently good to fool the human mods who approve / junk comments.
what do you mean, 'trustworthy' - it doesn't really 'do' anything - you still have to fill in the comment by hand. You can find blogs with google, of course.