I've just started using the elliptical for 30 minutes per session, and walking an hour (alternating in days)?

I will walk 3 days a week for an hour, then swim an hour after that, and between those days do the elliptical for 30 minutes, and if I'm not too tired, swim for about 30 minutes if I'm not too tired - totaling 5 days a week of working out, and keeping my weekends as my rest time as these are my only 100% me-time days. Is this a good workout regimen? Please tell me your experience with the elliptical, or walking. How long did it take you to lose a great deal of weight in sticking to this program? Not this specific one, but at least using one of these methods. I've heard a story of my friend's friend doing elliptical workouts for 30 minutes, three times a week and he lost 30 lbs in a month. Is that possible? Please give me tips on how to get the most out of these workouts also.