I stumbled across this one and have been impressed with how it functions.
I tested it at first with just my own gmail based Google Calendar to see how it looked. And it looks good. I find with many of the calendar components that the overall design is lacking - and not being a great designer or coder myself, I find it hard to modify them.
So the design is really neat - and you have the two options of using the Google Calendar iframe view or a nicer looking embedded view.
So then I setup the calendars from my Google Apps domain (for the site I'm building). I ran into some troubles here - but this was mostly due to the PHP setup on my WAMP server. Also had a bit of trouble with some SSL peer verification but was able to quickly find a fix in the forums.
Now I have my site running and able to display multiple calendars for my organisation - for example I have a generic calendar as well as a staff specific calendar - colour coded just like it is in the Google interface.
Overall, I'm pretty impressed with how easy this component has been to install and implement.
Finally, with this one, I found something that does.
I use it to make life a little easier for clients who want to add content to their sites. They can just email it in and then tidy it up from the backend.
I did have trouble getting gMail or Google Apps email accounts to work with the component - so in the end gave up on this (for now). It all seems to be around the ssl stuff with these, so I just created a standard POP account on another server.
I see that the issue with gMail is meant to have been sorted - but I've not been able to get it working.
But even with this problem, I'm very happy with the component.
The jobs look nice on the site and the additional module allows me to display current positions on pages other than "Current Vacancies".
The only thing I had trouble with was with my choice of WYSIWYG editor - the window isn't big enough to fit all of my choice of editor in making it a little difficult to edit jobs.
Overall, a simple and elegant solution to a common requirement in many websites. Well done.