A friend of mine and I are traveling to Lisbon for a few days and are looking for a good place to stay. Does anyone have good suggestions on a budget-friendly hotel that is in a fairly central location? We are trying to find somewhere that we can walk or get convinient public transportation to sights, shopping, nightlife, etc. Thanks!

Lisbon is one international city where there are many budget friendly hotels.
You could try the search here: Lisbon hotels/Portugal.

Also, it might help if you give people an idea of your cost limits.

If you want to be close to most of the top sights for walking, you probably would want to check the Baixa or Chiado areas. But public transportation in Lisbon is very reasonable, even the taxis.

Good luck.

Thanks for the suggestions. We are hoping not to pay more than 90 a night since we are both on a budget.

Is this too budget for you?
http://www.lisbonhotelborges.com/
We were there a few years ago and though it's a bit faded, the location can't be beat and it might have had a makeover by now!

DubTraveler. I didn't suggest a hotel as the last time we spent a week in Lisbon it was at an apartment.
I think on that budget, you will have not trouble finding a very nice place.
If you are interested in an apartment, look at VRBO #146014. This is where we stayed and the apartment and location were fantastic. Of course, it only has one bed, although a large one, so if you need two beds it won't do.
The owner has several places and may have another option for you. But of couse with an apartment there is no maid service or breakfast.

No matter what you decide, you will have a great time in a great city.

I stay at Residencíal Estrela do Saldanha: Avda Republica, 17. Carlos Ferreira, co-owner / Manager speaks reasonably good English. It's well located: at the Duque de Avila exit from MetroLisboa, Saldanha Station-stop, and one long block from Praça Saldanha where you can catch the #28 TrolleyBus.
It's adjacent to Pasteleria Versailles (a 'Golden Oldie') and there are several economical restaurants around the corner on Duque de Avila..

It's also not too far from SeteRios main Bus Terminal, or EntreCampos Tranvia Stations.

Once you get on MetroLisboa you can get anywhere in Lisbon within 30-min.

This was a good one when we visited several years ago and it was in the process of being renovated:

http://tinyurl.com/b2ge6r

There is decent access to the metro and the breakfast buffet was good. Lisbon is a great value in comparison to other western European destinations. Enjoy!