North Stradbroke Island has everything you could ask for from an island paradise: long white sandy beaches, secluded lakes, scenic walks and picnic spots, heaps of interesting wildlife, and an excellent pub. But the best thing about 'Straddie' is that only a short ferry ride stands between you and the island's wonders, thus making it a very easy day trip. The only difficulty will be forcing yourself to get on the return ferry at the end of the day.
There are many companies that offer day trips to Straddie, thus allowing you to take in the main sights of the island without worrying about how to get to them all. The tours focus on a variety of themes, from eco tours to whale watching, ensuring that there is something for everyone. Just Google 'Straddie Day Trips' and take your pick.
Be warned, it is likely that one day will not be enough (personally, I don't think a week is enough). Lucky for you, access to the island is simple and cheap – Stradbroke Ferries and The Big Red Cat provide passenger and car ferries leaving regularly from the Cleveland ferry terminal, just 30 minutes from Brisbane city.
The ferry will take you to Dunwich, the closest town on Straddie to the mainland; from there you can begin your island adventure. Some of the must-see sights on the island are Point Lookout, which is Queensland's most easterly point, Brown Lake, Cylinder Beach, North Gorge and, of course, the Straddie pub.