events calendars in rails appllication

I am currently working on a rails application, which is supposed to allows users to create events (holidays) and view shared events on a calendar. the requirements are simple. the required calendars are merely views. there is no interactivity needed other than providing links to the events.
so like any rails enthusiast, i went to Google and assumed i would find plenty of stuff to help me. it turns out my expectations were too high.
i found one worth while simple rails integrated calendar, its the calendar helper, which is bundled as a rails plugin. you can find it here : http://topfunky.net/svn/plugins/calendar_helper/
the plugin provides a function that can be embedded in a any view to create a calendar. its CSS is not that good. it however provide a starting point.
another option we had is embedding a Google calendar. the idea is that the rails application will have a Google account from which it can manipulate events on the calendar. Google calendar does provide a lot of integration libraries in many languages( php, .net ). sadly though, none for rails or ruby. there was one plugin for Google calendar that was available for rails (benjamin.francisoud.googlepages.com/googlecalendar). we gave it a shot .
problems we faced :
the plugin doesn't pick up the event id (provided by google ) after inserting. so you can really update events ( you have no reference id to them) . and even API doesn't support any of this functionality. i.e the plugin only lets you insert events ( no edit, deletes, or updates) . (this is what we found at the time of this post).
We are working on getting this calendar into a shape, and we will release the new code once we think its mature enough and usable by others.

Reuse and API

the most efficiet approach to building systems today, lies within reuse. as open source software grows, and we get better and better open source applications like ( all the php(s) in the web application world) . so now you are faced with requirements to build a new system, you could easily see that most of the functionalities were already implemented in open source, maybe not all but most . now if you are smart enough you will think of reuse. which will make the task easier. and the developement time shrinks. but we are still afraid of such endeavor , and most developers rather rebuild the system from scratch ! And i am wondering about why this is the case?
my conclusion is that : in order to reuse any "component" in software, you need an API for it, a very good API, that is well documented! and in general building a component with mindset that is targeted on reuse ! it's like design for testability really, if you dont think about it early on its hard to achieve !

there was a vey nice google talk about designing good APIs and why it matters to do so : you can find it here: http://youtube.com/watch?v=aAb7hSCtvGw