Oh, wow, a bunch of questions for me. I'm going to start feeling spoiled.

Unfortunately, being at work, I don't have time to spend answering them all in detail (of course, you saw what my "in detail" posts looked like in my first two posts). But I can give "quick" answers and expand on them later if you want.

JP - I have two setups on three computers, all dual-boot. My desktop computer has a second harddrive, with Linux on it's own harddrive (and since I then recently upgraded my Windows harddrive, I had a spare sitting around to play with). For my first foray into Linux, that seemed to be the safest and easiest way to go. Since laptops typically don't have a second harddrive, my wife's laptop and my work laptop are both partitioned.

JP and St39.6 - (JP really didn't ask, but I think it was sorta implied.) Windows XP typically uses the NTFS file system, which Linux doesn't really like (Windows owns the specifications for that file system, which are very complex, and don't let just anyone see how it works). Ubuntu treats NTFS as read-only, so you can read the information, you just can't change anything. Older XPs may use the FAT32 file system, which Linux can read just fine. But Windows can't read Linux partitions (or should say, won't read, since that information is freely available for anyone, even Microsoft, to use). So I have Windows on NTFS, Linux on ext3 (I think), and I created an extra partition on my laptop (and I have several partitions on my desktop) as FAT32, which both Windows and Linux can read... kinda of a DMZ on my computer. For the laptops, on a 40 GB harddrive, I have a 20 GB Windows partition, a 10 GB Linux partition, and the rest as a FAT32 partition.

I just read that it looks like the next version of Ubuntu next month might have better drivers for NTFS, so that limitation may change.

St3.9 - It is my experience that Linux runs faster than Windows on the same system mainly because there is less bloat in Linux (smaller programs usually mean faster performance). Linux also has less system requirements (The latest version of Ubuntu recommends a 500 MHz processor, 256 MB of memory, and 10 GB harddrive... Windows Vista recommends 2 GHz processor, 1 GB memory, 40 GB harddrive and a DirectX9 video card.) But Linux does not experience the same slow-down problems that Windows has (I don't have time to go into the disaster that is the Windows Registry right now). You also don't have to worry about defragging your harddrive, and it isn't as critical to run anti-virus... some say you don't have to run AV at all, but after years of working with Windows, I just don't feel comfortable without AV. There are some viruses for Linux, but they are rare and they don't work that well (there are dozens of Linux virus compared to tens of thousands of Windows viruses).

A rather long "short answer", but I didn't want to leave important stuff out even if I don't go into as much detail as I can or would like, although probably going into more detail than I should.