Compressed files

I know compression and creating of image files is a daily activity for the expert Mac user. But nowadays people have both PCs and MACs in their house. So there comes times when one needs to like for example, your Mac crushes and you don't have the Setup Cds or anything like that, so you need to download a utility disk from the internet and use it to boot up your system. But the program is in compressed form. So you need to decompress it with a program like Aladdin Stuffit expander for both windows and Mac. But for those of us who have Low band internet connection you can't really download it in good time. So my quetion to you is, do you have any links to other programs that can be used instead of Aladdin Stuffit expander? One that can specialise on .sea and .bin files? And if not, shouldn't someone be thinking of making one?