One key point: you don't mention anywhere in your question why you want to transfer. Because you say "some PhD programs", I gather you don't have a specific other program in mind, and I can only assume that you don't have some compelling personal reason to do so (e.g. living in a certain city so as to care for a family member) but rather are simply trying to trade up.
Most students who enroll at programs which are not the top ones in their field would like to (or should like to!) move to better ones if they could, but because transferring programs is a fair amount of inconvenience for everyone, the threshold for doing so is rather high. If you want to get into a better PhD program in year N+1 than you did in year N, then it would be reasonable to have a better application.
Trying to improve your application while newly enrolled in a PhD program is a bad idea. First of all, as everyone else has said, of course you must disclose the fact that you are currently enrolled in a PhD program if you are applying to a different one. The idea that you think otherwise is a bit alarming, not because this is such an evil thing to do but it shows how far away you are from understanding academic culture. Do you think that no one will find out that you are currently in a PhD program?!? Think again: likely all of your recommendation letters will mention this, for instance.
Moreover, the first semester of being a PhD student is a tough time to build your application: no one at your new program knows you very well (or at all), you haven't done anything much, and more than likely you are just absorbing the culture shock of a new environment and are not in a position to show superiority (and in fact most first year PhD students are fairly inept compared to other PhD students in the program: I know I was). This phenomenon comes up when first year PhD students try to reapply for certain graduate fellowships (like an NSF fellowship) that they were also eligible for as a graduating undergraduate: they have to get a mix of recommendation letters from faculty at their old university who probably have nothing new or better to say about them than the previous time around and from faculty at their new university who have trouble saying more than "Mr. X is a student in our PhD program -- isn't he? I'm pretty sure."
My advice is to do one of the following things.
Ask the university who accepted you whether you can defer for a year. It is much better to ask this question up front than for them to find out later from someone else that you are trying to trade up. It is a fairly good bet that you will be able to do it: I would much rather enroll a student a year later if in that intervening year they figured out that they really want to come.
Enroll in a non-PhD program either there or somewhere else: a non-degree program or a master's program. In the American system, getting a non-terminal master's degree is essentially the culturally accepted version of the kind of academic laundering that you seek to do. This is probably two years rather than just one year, and if you play your cards right you can actually improve your application and profile in that time.