How Long Does a Laptop Last?

We are currently considering replacing a Sony Vaio VGN bought in 2004, and my partner was shocked that her laptop only lasted ~3.5 years.  I was shocked it lasted that long, but I suppose I ride my machines harder (not only operation-wise, but I tend to knock them around physically a bit).  In my experience a decent (good) laptop lasts around 3 years, and a lame (budget Dell or Gateway) laptop lasts around 2 years, if you work at it.  I once managed to keep a Dell running for 3 years because I inherited a full-service warranty which lasted that long...

After trolling the internet I've found a number of conflicting opinions.  Some users, for example, who never let their laptop out to play on the internet have had VERY long lives.  Some (mainly mac-users) claim their laptops should last a minimum of 3 years, and usually max out at about 5, with the average lasting somewhere near four years.  I would expect something like a Sony Vaio, or a high-end HP to last that long on the PC side; but then again, I don't know if anyone has had that experience.  I'm on my first HP laptop now, less than a year old; so I will update this post once a year with a check-up; but in the meantime I invite the readers to vote on your experience. How long does your (average) laptop last??? (See poll on right)