Due to the lack of a LinkedIn client for the PlayBook many people have been using the functional LinkedIn website. inLink is hoping to fill that gap by using the BBUI.js framework to create what starts to look like a BlackBerry 10 app. It allows you to check your latest info on LinkedIn along with finding and applying for jobs. You can also view your mail and quite a few other functions. In short I find it better than the sideloaded Android app I was using until now.
If you want to try another way to access LinkedIn on your PlayBook then check out inLink for $1.99 in App World.