I can make an image of the drive, then wipe the machine, and restore it back to its former state if I ever have to return it.
Is your new job worth it? Not saying you'll automatically lose your job over that, but I can't imagine it'll go over well. Especially as you'd be using your (non-work prepared) laptop for doing work and might inadvertantly put them at risk (the kind of risk they hope to eliminate by issuing you the laptop in the first place).
The simple solution is get yourself a USB / livecd type distro. Don't touch the hard drive.. and if it's encrypted, you shouldn't be putting your company at risk (assuming you don't use the same key for anything else). Personally I'd ask your IT guys if they are ok with this before doing it. Sometimes they can actually be reasonable about this kind of stuff.
The real solution here is to leave your work laptop alone completely and get your own laptop for personal use.
The parent correctly points out that you can use a live distro and avoid having to touch the company's hard drive.
Maybe, maybe not. There may be key-loggers installed which still grab your keystrokes.
Further, you can set up machines to prevent booting from anything other than the hard drive, then lock the bios.
Just to be clear, OP is saying he is "not the type of person who can't look at pornography" right? In this work-related scenario, if that's the case, get your own laptop, tablet, or smart phone.
If that's not the case and he is worried any personal use will get you in trouble, that's probably something he should clarify. I know plenty of unreasonable work places are around, but it is unreasonable to expect no personal use from a company laptop in constant possession of an employee (especially outside of work hours).
If neither is the primary case and you are expecting the laptop to be so locked out that you can't run anything but an office suite and the company-modded IE-engine software, then, as was pointed out, run a separate OS off a thumb drive. If the hardware is completely locked-down, back to the tablet/smartphone concept. Look up the policy, talk to the IT guys, but, essentially, DON'T do something that can mess up IT's carefully locked down security, and DON'T do things that are illegal or NSFW.
If the issue isn't "I want to look at pornography on my work laptop", why would the company care if he reads an ebook or watches a movie, if it's done responsibly (and somewhat out in the open, so all that's monitored is a lot of "unknown activity")? It kind of sounds like it's a porn thing, though. Maybe it's the inferred metaphorical air quotes.