Text search within Safari page on iPhone3G

Ive looked at the instructions in the iOS4 user guide for searching for text within a web page. Ive tried it on my 3G with iOS4.2 and the in-page search options dont appear at the bottom of the Google suggestions (as specified in the manual).
Theres nothing in the guide that suggests this shouldnt work for iPhone 3G. I have three questions:
1. Should it work with iOS4.2 on my iPhone 3G?
2. Is it merely a delayed feature scheduled for a later release for the 3G?
3. Where can I find clear, comprehensive lists of what features are available in iOS4.2?
iPhone 3G iOS 4