I've actually got the second of the two Rudin books you mentioned sitting on my hard drive. I skimmed the first few sections of the first chapter on measure theory, and while I don't find this material to be over my head, I think I'm looking for the material in the other of his books you mentioned, the one that concerns itself with proving things about calculus.
Here, I'll be more clear about the math background I have. As of a year ago, I've taken the engineering courses at cornell on single variable calculus, multivariable calculus, differential equations, and linear algebra. These were all taught by math faculty, but they were geared toward providing us engineers with a working knowledge of this stuff. So, these classes sacrificed some rigor for the sake of covering more material (except for linear algebra, which was nice).
Currently I'm near the tail end of a course on topology taught by the math department for math majors. The first 2/3 of the class was dedicated to getting a hold on such concepts as compactness, connectedness, quotient spaces, etc.. Now, we're doing some introductory algebraic topology: defining the fundamental group, covering spaces, classification of covering spaces, etc.. The class has been great fun for me and, as a result, I'm keen on learning a good deal more about mathematics.
Seeing as I'm currently a senior applying to graduate schools for plasma physics, doing this will involve me reading textbooks on my own. As most math books assume the reader has experienced some sort of introductory exposure to analysis, I feel it would be appropriate for me to gain just this sort of exposure. Furthermore, because I already know some topology, it would be expedient to learn this material from a text that doesn't avoid using topology.
Do you have any other recommendations for texts with a chapter on topology early on, besides Rudin?