One of my customers sent me the following:

"We have a child object connected to Opportunities that is pretty simple – it consists of a couple of text fields, a date. Reps use it to record “next steps” for opportunities. What we need is the latest “Next Step” created related to an opportunity to populate a field on the parent opportunity with one of its text fields. This way, the latest “Next Step” can be included in reports along with opportunities and their products. I still haven’t looked into it too much but if it’s possible, I believe it’ll have to be a trigger. I guess the high level requirement here is we want to record next steps as deals progress but we also want the latest one – and only the latest one – to fit into a funnel report that is used to manage calls, etc."