Austin Texas (1 Viewer)

[PhotoSyko]

My only guess is some kind of warbler?

 

[THE_FERN]

Looks like female lesser goldfinch (note wedge-shaped beak which shows it's not a warbler)

 

[Butty]

When faced with an unknown bird, always look first at the bill. As Fern points out, this shows immediately that it can't be any warbler (as your field guide will show you). It's a goldfinch, and, like Fern, I should think lesser goldfinch, which has a more stubby bill than American goldfinch - on plumage (other than breeding males), I find these two a problem to separate, and in this case the only reason I'd guess lesser goldfinch is that it looks more nondescript than normally do the various American goldfinch plumages.
It's important when asking for an ID always to give the date as this may often be important in determining which plumage the bird is in, and thus its ID. In my opinion.

 

[AveryBartels]

Another for Lesser Goldfinch, for the reasons stated by the others