AmazonBasics 4 Port USB 3.0 Hub
Laptops are great because they are portable and light weight. Their one downside is they only have 2 USB ports. Whenever I see the back of an iMac, I'm extremely jealous of the 4 ports. Thankfully, Amazon sells powered USB 3.0 hub for $18.99. This will allow you to hook up USB ethernet, a time machine drive, a printer, and your iPhone while still leaving 1 port free.