Custom SharePoint JavaScript field type

I'm in the need to create a custom field type that renders like a LinkValue field. Instead of forwarding the browser to a different 开发者_StackOverflow社区page, I would like to execute JavaScript code (in order to use OpenPopUpPage) depending on several parameters (maybe stored in SPFieldMultiColumnValue?).

What is the best way to approach the requirement?

This has to be the best reference on custom field types from Bjorn Furuknap

Customizing the User Experience of SharePoint: Custom fields deep dive

There is some pain involved in custom fields types though, in his own words

“Looking back I think it would have been easier, and less painful, to eat my own eyes.”