If you are going to go the mobile broadband route then make sure that the one you go for has a good signal in your area.
For instance druid's 3(three) router would not work here, we don't have any signal at all from 3.
I also live quite rural and use a slightly different technique when the landline is playing up or being slow.
I 'Tether' my mobile phone to the laptop using the USB cable supplied with the phone. (I'm doing it right now).
What you are doing is using your smartphone as a router to link your laptop to the phones mobile data. (3G/4G depending where you live).
You probably already have a data allowance if you are on some kind of phone plan, so this is not costing you another monthly fee.
Even PAYG plans usually have some data allowance these days.
http://ee.co.uk/help/my-account/pay-...-how-they-work
How to do it?
Make sure your phone is set to recieve mobile data.
Connect to your laptop using the USB cable. It will tell you it's connected as a media device.
On the phone go to Settings>Wireless and Networks>more settings>Tethering and portable hotspots (or similar wording, depends on your phone).
Select USB tethering.
After a moment your laptop will show a new ethernet network and connect to it.
Make sure that you set this network as a metered connection, you don't want automatic downloads using all your data allowance.
A slight bonus, while you are connected this way the laptop is also charging the phone battery.
You may have noticed when you were in that settings screen that it is also possible to set your phone to be a 'Portable wifi hotspot'.
That's another way of connecting your phones data connection to your laptop, but without the cable.
The phone gives out a wifi signal and you connect your laptop to this.
Of course this uses more of your phones battery, and there's an initial password to set up to make sure nobody else is using your phones wifi signal.