Yes their is a way of doing it without copying to the hard drive first but you could look at it two ways. The first would be burning on the fly (copying directlly from disk to disk). This method is highly not recomended. If the data transfer slows down at all, even for a moment, you have a coaster. If you mean without you having to manually copy it to the hard drive yourself (using dvd decryptor for instance), yes and this way works great. You need anydvd (unfortunatlly its 40$ but well worth it in my opinion). Anydvd runs in the background and removes copy protection as well as region protection and user prohibited functions (like when you cannot fast foward through an add or copy right warning). It just runs in the background and you do not have to do anything with it. It will make the disk apear like it does not have copy protection and it will work with any program. You are not copying on the fly. The movie will be copied to the hard drive but it does all that in the back ground.
For instance I use nero recode and anydvd. I insert the dvd I want to copy and a blank disk. I click import, choose the movie (it usally has it auto selected so you just click ok). It does a quick analysis (about 1 minute on my computer). I click next, click burn and walk away. In 16-40 minutes with an 8x disk, the drive ejects the blank (which now has the movie recorded on it) and thats it. It does copy temporary files to the hard drive during the process but I don't have to deal with it. If you only have one drive, it will eject the movie at the right time, you insert a blank and close the dirve, and it continues on it's own. Other programs like clonedvd will operate in a similar manner when using anydvd. It doesn't take more that a minute or two to start it and then you can walk away when and come back when it is done (swaping the movie for a blank if you only have one drive of course).
That of course is using pay software. Many use dvd decryptor and dvd shrink. They do a good job and they are free but there are some extra steps you have to do yourself (like ripping it to the hard dirve first).