There is an easy way to change the clock-multiplier for the portege 300CT laptop. This will change your cpu speed from 133Mhz to 166Mhz. Why would you want to overlcok a 4 year old, clunky, slow laptop? Well, because you CAN! Oh, and I do still find mine very useful. Overclocking it has allowed me to get a bit more life out of it. Also, with prices for these babys dropping to near nothing on ebay, you can get one and have some fun with it too!.
To do this, you have to TOTALLY disassemble your laptop and do some light soldering. This is not for the faint of heart, and let me just say right up front that I'm sharing what I did to MY laptop so that you can do the same if you wish, but the responsibility is all yours -- if you break it, or if you can't get it back together, it's your responsibility.
If you dont have experience soldering this is probably not the first job you want to practice on, but it's not particularly taxing... Get a friend to help who has a bit of experience. Heck -- I'd be willing to help you if you're in the Provo UT (USA) area -- buy me a pizza and we'll have it done in no time! (or if you're really sick twisted and desperate, ship me your laptop and I'll do it for you for $500 :) That price is sufficiently high to scare off anyone I hope, but it's at least enough to cover hardware replacement if I toast your box and still make it worth my time...
So, there are two solder-pads labeled W4 on the bottom of the main motherboard in this laptop - bridging them with a small piece of wire will do the trick. After a bit of experimenting one of my friends discovered that the clock multiplier is only checked at cpu-initialization time (at boot time) and that the signal is low-asserted. With a small diode (for exanple a 1N914 that you can get at radio shack for pennies) and some work you can wire the low-assterted power-switch on your laptop to control at power-on time wether you want to boot 'fast' or 'slow'. Running overclocked generates more heat, and uses more power and runs the fan more, so when I'm on battery, I boot 'slow'. When I'm stting at a desk, and the laptop is plugged in, I boot 'fast'. Merely tap the power switch to boot normal, or hold it down for about 5 seconds to boot fast. Couldn't be simpler. Or, if you dont want to bother, you can just solder a wire across the two jumpers and away you go.
I got my infomation and ideas about overclocking from the following two websites, niether of which I could read, but which had great pictures...
http://www2.justnet.ne.jp/~toshio_h/por300.html
http://www.crosswinds.net/~williewien/links.htm