Moving and need advice

[#1]

I will be moving to a temp cottage and the problem is, the phone point is 30 meters away in the main cottage.  The cottages are linked up and access is via doors, but very thick walls.  For the few months we are there its not worth the expence of getting someone in to put in a phone extention as money is extremely tight.  Its not our place either, but  its allowing us to be able to sell our property and get out.  I have a DSL-2740R router,( I would advice no one to get one of these by the way).  Is there a way I can set up the router and get access 30 meters away with something wireless to my main computer.  I really need access to the internet and don't know how to resolve the problem
Thanks for your help

[#2]

If they use the same electric supply you could use homeplugs: http://en.wikipedia.org/wiki/HomePlug
This way you can move the plug around with you, not as portable as wireless but it's an option.
They don't work between houses as the electric meter filters out the signals, plus if they don't have the same incoming electric they may be operating on different phases. If they are on different power supplies I'd also be hesitant to run a long networking cable between them as this could be dangerous as there will be both using a different earth and this could damage your equipment.

[#3]

Thank you worth looking at and thinking about