How to create a itinerary planning website?

I have an idea i thinking of creating a website whereby a traveler can exchange itinerary activities and form their own ideal itinerary.

Any ideas? Has a similar website been done? Is it worth comin开发者_高级运维g up with another similar application?

This depends on your end goal.

If the end goal is to implement an app useful for yourself as an intended user, you might want to google for "social itinerary" and see which of the top 10 results tickle your fancy... refine the query as needed (a 3-second Googling yielded me a mention of TripIt, for example). If, say 1 hour of research doesn't yield any useful results, may be building your own is then worth it.

If the end goal is to get programming experience from what sounds to you like a fun and may be useful project, go for it - it's worth it.

If your end goal is commercial (e.g. make money off it), no offense but you don't sound experienced or skillful enough to execute this well enough to make money; based on your question (you ask if it was done on SO instead of a quick google, for goodness sake) - even if it was a good idea, execution is 99% of what's needed to make money off it. So not worth it.