You got a .rar file and you don't how to open it, some one asked you to send him "a rar file" or you just need a good archiving software? Download and install WinRAR.
Not only that you can share files — like documents, images, and PDFs — without having to email them as attachments. You can share the whole folder containing the documents.
You can upload and import any MS Word document file to Google docs/drive as you can download and export a Google docs document to you computer and open it with MS Word.
Nokia released the Here Maps app for iOS devices. You can use as a turn-by-turn navigation, search for interesting places, buses and plenty more for free. This is how you install it on your iPhone or iPad.
TinEye is a great reverse image search online service, that can tell you where an image came from, find different sizes of the image and you can find out if someone is using your image without your permission.