W/respect to your phone, you'll want to Google for what's known as "tethering".

Also, you'll want to find out if your laptop has built-in wireless (802.11) or not. If not, it's probably worth picking up a cheapie 802.11 USB adapter. Even if your relative's place doesn't have Wi-Fi...you may be able to pick up a signal from the surrounding area and "borrow" it. This may be considered a moral/ethical gray area...some people don't approve of it, others don't care. But it works. Wi-Fi adapters are so inexpensive these days that unless you're flat broke buying one shouldn't be that big a deal.