Set of icons update

As you know, I have been working during my free time (that is not much these days) on a set of icons that I'd like to share with you. There are not many of them yet but just when I tried to release a first beta version I stumbled upon the great news: "Icon composer" is no longer inside Xcode 4". I used to use Icon composer to wrap my icons in sizes 256, 125 and 48 pixels. I have tried other applications but haven't succeeded. The results are not good whatsoever.

So here I am, asking everybody for ideas. Or I just might take the easy solution and release PNG's instead of ICNS.

If you know about any tool that would help me to wrap icons for each size then let me know. Oh, and I'm not interested in paying much money for them. So it has to be either cheap or free.

Thanks in advance guys!