Not sure if Android 1.6 is supporting tethering...
Try a google search for "android 1.6 tethering"
I think I saw an app to do this with the mini.

Anyway, Android 2.2 does support tethering, but as you might know, SE is just going for the 2.1 later this month (well, that's the plan, so look out for the update).

The X10 mini is nice to look at and to hold in the hand, but the inside sucks the more you try to do....after all, it's a "smartphone"...or not?

 

yo, there's some app to tethering your xperia x10 mini
unfortunately, I kinda forgot the step, haha

well, maybe the greatest way is root your mini and make it as a portable wifi hotspot, just like me

there's a simple step to do it
First, you can use Universal Androot to root your phone in just one click
After you rooted your phone, go to the market and search for 'Barnacle WiFi Tether', and install it

then ... Finish !!

Now you've got a portable wifi hotspot on your pocket !!! GREAT !!!


nb : I installed 'BusyBox installer' first time when rooted my mini back then, however, I kinda forget for what, hehe, maybe you should try to install it too

Maaan, I'm just a newbie anyway
Just try to help, haha