HTC Desire S is a lovely phone. It will be more lovely with ICS. Here are two posts for ICS custom ROM update for ICS. Which process is the best? What do you think?
1) ICS on HTC Desire S | Android 4.0.4 Update | A Step by Step Guide
2) Update HTC Desire S to ParanoidAndroid ICS 4.0.4 Tablet Hybrid CM9
1) ICS on HTC Desire S | Android 4.0.4 Update | A Step by Step Guide
2) Update HTC Desire S to ParanoidAndroid ICS 4.0.4 Tablet Hybrid CM9