--Here's something I noticed right off the bat:

[[ Before I start to explain my problem I want you to know my system details:
Knoppix 3.4 HDD-Install
AMD K6 500Mhz
192MB Memory
8GB HDD (1GB Linux Swap)
Connected to Internet via DSL over Router
10Mbit LAN
]]

--First of all, an AMD K6 is not the best thing to be running a server on. Personal experience with older AMD's tells me they're flaky, and generally slower than Intels at the same speed rating. If you can get a faster (used, even) machine with an Intel (or AMD Athlon/Duron) of 800MHz or better, that would be a good step. However, I realize that $$$/resources may be limited, so I will try other suggestions as well. (My "fast" machine is currently a 900MHz AMD Duron because they were more affordable at the time, so I know whereof I speak.)

--Try enabling DMA and 32-bit mode using hdparm:
' hdparm -c1 -d1 -u1 /dev/hda '

--This should speed up the hard drive. (If you start getting DMA errors, shutdown immediately and reboot - and do not re-enable the hdparm.)

--Increase the RAM to at least 256MB, if possible. More is better. If using the machine as a server, do not run anything else on it (disable all GUI, and do not use it as a desktop machine.)

--Replace the 10MBit LAN card with 100MBit. Trust me, it makes a difference. However, you also need 100MBit infrastructure (hub/switch, cat5) to really take advantage of it. Personally, I was happy with 10mbit myself until switching to 100. Worth the investment -- 10mbit only does about 700KB/sec, while 100mbit does ~10 times that.

--Recompile your kernel. I can send you a sample config file, if you want. Especially if you're using the default one that came with an older Knoppix, it's worth your while to tweak it for your specific hardware -- you can save disk space (delete old modules after you get things working right) and memory, and compile things for your specific architecture. My Linuxtips page at the bottom of all my posts has more info on kernel recompiling.

--Outside of that, I know there are things to speedup Apache and the rest, but I don't have personal experience with them. (I'm currently only running Squid on a 233MHz Pentium-1 for my Internet needs.) Your best bet is to google around for speedup tips, and maybe find a guru in your area to also help you with config tips.

--BTW, what kind of web pages are you loading?