Minimalist for Google Calendar is very similar to its Gmail-based brother: it lets you tweak all sorts of different interface elements of Google Calendar so it fits what you need. Don't need the "other calendars" box? Remove it. Want a link to Google Voice at the top instead of to Google Docs? You can change it. You can also change the colour of nearly any part of the page, as well as even remove things like the mini calendar and logo to make it more friendly to netbook screens. There are a lot of settings buried in this extension, so if you're a Google Calendar user, check this extension out — you'll probably find a few things in there you want enabled.
Minimalist for Google Calendar is a free download, works wherever Google Chrome does.
Minimalist for Google Calendar [Chrome Web Store via AddictiveTips]