Last year I read on low end mac about a web browser that would run on a G3 (15+ y.o. machine) and could display the new features of the internet. Although I imagine that watching video would be out. One neat thing about this browser (who's name I disrecall) was that you could set it to report the name of whatever browser you wanted - a good way to force webpages to display and possibly a way to fool hackers.
Actually the G3 came out in 1997 or 98. I had one on my desk--back in the G3's heyday, I worked on both Macs and PCs. By about 2000 or 2001, it was no longer a machine you would want to use every day, unless you don't mind waiting a long time for applications to run. You can install some versions of OS X on them, but OS X was never fast on an original beige G3. Trying to do modern computing on a G3 is very much like trying to run Windows XP or Vista on a 400 MHz Pentium II. Nothing stops you from doing it, as long as you have the amount of memory stated on the box. But that doesn't mean you would want to do it. I've seen Windows XP on a 133 MHz Pentium from 1994. It works. It wasn't fast, and I didn't like using it, but it worked.
As for spoofing other browsers, Opera (on all platforms) has been doing that for a number of years. It's a common feature.
Others in this thread have already spoken of the long term value of Macs. As for using the internet with an XP machine, one problem that I've had is that the hard drive on the machines I use is always being accessed. My friend who has a degree in computer science says that is the result of hackers who want the infomation on your harddrive.
Umm. Go back and ask your friend with the degree in computer science about virtual memory. It's true that spyware can cause the disk to thrash, but another, very likely explanation is that your XP machine doesn't have enough RAM in it, and is using the hard drive as a cheap substitute.
I'm typing this right now on an XP machine. My disk light is off.
And while it's not as common as Windows spyware, Macintosh spyware does exist. I read about some just this past week. And have you heard of pwn2own? It's a contest where they set up a Windows box, a Mac, and a Linux box. First guy to hack into it gets to keep it. Not only does the Mac get hacked every year, frequently the Mac is the first one to go. For what it's worth, someone manages to hack into all three systems every year. The only secure machine is the one that's not plugged into the network.
You couldn't pay me a million dollars to e-file my tax return.
That's what encryption is for. Encrypted links can be made extremely secure, when necessary. I've been e-filing for years.
Oh, I forgot: it would seem to me that finding which drivers you needed without system documentation would be a difficuolt proposistion, and then finding drivers that weren't virus carriers would be, too. Not that I've ever tried to do these things.
It's not that hard. Functional drivers often are included with the OS. If you don't have one, look on the card. Most network cards use one of a handful of chipsets, for example. It's a good skill to develop. It helped me pay my way through college.
To avoid viruses, download digitally signed drivers from the manufacturer. If the driver has been altered, the digital signature will be invalid, and Windows will lay an egg when you try to install it. And futhermore, you DO have antivirus software installed, don't you? Microsoft Security Essentials is a good, effective antivirus program, and it's free. Don't trust Microsoft? Then I recommend NOD32, published by ESET. It's effective and slows your system down less than any other antivirus program I've seen, because it's written in assembly language.
Speaking as a computer security professional (I'm Security+ certified and currently studying for my CISSP), please, since you've expressed concern about computer security, learn something about it. Spreading assumptions and misinformation about computer security doesn't do anybody any favors. Please, by all means, read up on encryption and digital signatures at the very least (the Wikipedia articles on them are a reasonable place to start).