dsl customers have a choice of what provider they use unlike cable the telco still have to share there lines, so just go with a uncapped service.
As another member has pointed out just because they have to share the lines does not mean it has to be at a fair or even reasonable price. For that reason ATT in my area ( far burbs of Chicago IL) has no competition from any company offering DSL over there lines. Not to mention that since Comcast decided to unobserved the area ATT is the only game in town.
Despite what many out here were told ATT years ago decided to not upgrade our area to U-verse, I/we were told by top end techs and department managers U-verse was coming in 2008-9. Now in 2013 I'm Still waiting and no Uverse why because ATT has a monopoly on the area. No competition means no reason to dump the cap or even upgrade our area to Uverse no matter how much we all ask for it.
If some company was to offer a type of MVDDS system out here( similar to OMG fast in miami ), see how quick ATT would up grade this area to U-verse to compete and never even mention a cap again.
Actually you do have options for DSL. It's just only up to 6megs. And chances are its from MegaPath/Covad/Speakeasy, DSLX or some other reseller/wholesaler.