How to create dual boot into Vista and XP?

My new Dell laptop turned up today. As agreed Dell have installed XP whilst also supplying Vista on a seperate CD-ROM. The logic behind this is the IT chaps in our company recommended it, something to do with company networks and drivers not liking Vista, but get it anyway for future OS upgrade purposes.

Anyway in the past on my own PC's I have formatted the hard drive and created two partitions with different operating systems on each, accessed via a dual boot up option.

What I would like to know is what is the easiest way of creating another partition on my new laptop and installing Vista and hopefully having a dual boot up option thereafter.

For example do I have to purchase third party software like Partition Magic, or can it all be done from inside XP?

Many Thanks,

Noddydog.