I generally agree with what people have to say about Apple notebooks, as they
are generally better systems all around. However, my doubts with Apple these days stem from the fact that Apple announced that they are going to be swtiching over to an Intel CPU next year.
I have no Idea of what Intel CPU they plan to use, and have no Idea of how the internals of these new Apple computers are going to be from normal x-86 computers, as well as how Legacy (Read Current) Mac Applications will run on these. --If you plan on keeping this computer for several years, I might want to consider an Intel based computer from the start.
Unfortunately, If you plan on running some form of Windows on your system, much of what people say about them is true, in the fact that Windows is much less secure, and much more prone to Virus/Spyware/trojan issues, due to the fact that this is a much more popular OS.
In short though, If you plan on getting a notebook, get a name brand that is recognised worlwide, IE, Dell, Toshiba, HP, IBM , as support for thses brands is much more comprehensive, as well as much more readily available worldwide. --For what it's worth, Apple also has good Tech support as well.
If you are going to get an x-86 based computer, I would want to suggest either an Intel Centrino based notebook as these tend to have the best battery life of all x-86 notebooks.
If your not concerned with Battery life, and more concerned with Computing power, I would suggest a AMD64 system.
For what it's worth, ALL notebooks that I know of come with an AC adapter as standard equipment. 12v Auto adapters, on the other hand are optional equipment.
Added Thursday, July 28, 10:57 AM EST.
I'd also like to point out that most of the computers that IT people are running will be some form of x86 processor. While it appears that the next generation of Intel based Macs will beable to run Windows, you are looking for a computer at least 6 months to a year before the x86 based Macs will be ready. Much as I like Macs, I would suggest that you get a windows laptop, and if possible, do a FRESH install of XP Pro. --Hopefully the computer that you get will NOT have an OEM version of XP on disk.