When it comes to computers, you want it all: the portability of a laptop, the extensibility of a desktop, as well as the sleekness of Mac OS X and the wide selection of software for Windows. After virtualising and dual-booting Windows on my MacBook Pro for well over a year, I'm done—done with slow virtual machines and "your hard drive is low on space" messages, done with having to switch gears to move from one OS to another. There's software and hardware I'm invested in that simply works better on a PC over a Mac (and vice versa) and I want it all at my fingertips every day. When you want to move between the two operating systems fluidly and get the full benefit of both a laptop and a desktop, a few techniques can marry your Mac notebook and PC desktop to live and work in harmony. Here's my current setup.
Share a Single Keyboard and Mouse Between Two Computers with Synergy
Adam's already run down how to control multiple computers using the Synergy KVM software, which is a fabulous way to save space on your physical desktop by only using one keyboard and mouse for your notebook and desktop. With Synergy you can also share your clipboard between machines, and seamlessly move your pointer from one screen to the other. One update to that article: The SynergyKM download for Mac is now here (the original host is MIA). In the Mac notebook/PC desktop scenario, you also only need one computer monitor, because your laptop screen serves as the second monitor.
Share Your Speakers Between Computers
Once you're committed to having two computers up and running, you've got to decide which gets your speaker hookup, right? Not necessarily. With a sub-$10 audio splitter and a male to female stero cable, you can hear the sound from both your Mac and PC out of the same speakers. I've got the splitter plugging into my Mac's audio out jack, and my speakers plugged into one input, with the stereo cable plugged into the other—and into my PC's sound card.
Set Up a Fast IP-Over-FireWire Network Connection
Since you're going to be sharing your mouse and keyboard—as well as your data—over the network between your computers, you want the fastest connection possible. If your Mac and PC both have FireWire ports and you're running Windows XP, you can set up a fast, one-wire IP over FireWire network between them. This is totally optional, of course, because most likely both machines are on the same local network. But IP over FireWire will offer a much more stable, wired, and speedy connection for working with files on the other computer than a wireless connection.
Decide Where Your Data Lives—Then Map Your Drives
The tricky part about running two machines at once is figuring out where your data should live (unless you have a NAS or central server, but that's beyond the scope of this setup, which is simply one tower and one notebook). Much of this has to do with how much hard drive space you have where, and what files you want to be able to take with you when you go. The big space hoggers for me are my music collection and my photo collection. My music I want to take with me when I travel, so that stays on the Mac notebook. My photo archive can stay at home, under my desk, so that's going on my PC tower's hard drive. (I also greatly prefer Picasa for photo management than anything I've seen on OS X.) Both machines should have automated local and remote backups going on. (I'm using Time Machine on the Mac, SyncBack on Windows, and Mozy Home on both).
Once you've figured out what data lives where, share your drives between computers so you can work with what you've got from either machine. Here's how to access your Mac's files on your PC, and your Windows files on your Mac.
What's Better on OS X versus Windows and Vice Versa
One can't make a holy-war-starting, controversial statement like "some software and hardware is better on the PC or Mac" without backing it up. The following is just my opinion, plus a few software licences and gadgets I invested money in on either platform. Your reasons for wanting both Mac and Windows may differ from mine, but here's what I'm using on each.
On the Mac: NetNewsWire, Quicken (purchased a licence), Quicksilver, Time Machine, GeekTool, and DevonThink (purchased a licence) are all superior pieces of software to their Windows counterparts, as far as I'm concerned. My Fujitsu ScanSnap for Mac and the built-in iSight are also two peripherals I'll only use with the Mac.
On Windows: I greatly prefer Digsby, Picasa, Chrome, SnagIt (purchased a licence), and EditPlus (purchased a licence) to their counterparts on my Mac. Preferences aside, there are also scads of Windows-only software you see day in and day out on these pages, including Windows-only portable apps (like the Firefox 3.1 beta portable version) that makes having Windows access a must.
On both Mac and Windows: Obviously Synergy is required to share the keyboard and mouse between systems, so it's installed on each. I'm also using the same KeePass database (stored on the Mac, accessed on the PC), and todo.txt file from both systems.
With a notebook/tower setup like this, you can travel and have all your files with you, but still get the horsepower and extensibility you need at your desk. If your job requires that you use Windows (like mine), but you still want your Mac, this alliance is also a great option.
How do you marry your Mac and PC? Any tips for dual-computer users? Shout 'em out in the comments.