First, don't confuse Toastmasters with Dale Carnegie. The Carnegie course is a one time shot. Toastmasters is a continuing education. Virtually everyone I know who has completed the Dale Carnegie course has stated thatat the end they tell you to check out Toastmasters. Save yourself a few $thou and just get to a Toastmasters club.
Toastmasters is much less expensive up front, and is a continuous process. As stated above, you will get honest, useable feedback. Most Toastmaster orgainzations meet for one hour per week.
Virtually everyone thinks he/she is a decent speaker, but few really are. Just watch someone running for office, or making a presentation at the office, you will see what I mean.
As an engineer (and I will assume you are, considering this location,) you have spent a lot of your life with your nose in a book, at a workstation, or in a lab. As you proceed in your career, you will spend more time in meetings, presentations, etc. You will most likely be the smartest person in the room, but unless you can (have the skill to) convince others that you really do have the answer, much of your engineering goes to waste. Just because the solution is obvisous to you doesn't mean it is just as obvious to others. Through toastmasters, you will learn to be effective and effecient in your presentations.
WRT putting it on a resume, that is a judgement call. It is indicative of continuing education, but if you don't put it on the resume, all is not lost. The resume gets you the interview, the interview gets you the job. Your Toastmasters experience will show through in the interview.
Full disclosure: I have been involved with Toastmasters for nine years, have achieved the highest award (Distinguished Toastmaster), and have won multi-state speech contests. I currently belong to an english speaking toastmasters club and a spanish speaking club. I don't do much in the spanish club but check timing, but I'm learning the language.