There are still aluminum and/or metal straight needles out there, although most people who knit with metal tend to knit with circular needles. (*) If you go to a large craft store (Michaels, Hobby Lobby, etc), you should be able to find aluminum straights. Also, INOX/PRYM makes metal straight needles (as well as circs), which you may be able to find a LYS. Another brand that's gotten attention lately is Hiya Hiya, which are stainless steel, and they make circs too.

(*) A lot of this is because it's more comfortable to knit larger pieces with circs, because the weight of the work is carried on the cable, rather than all going onto the needle, which has to be supported by your hands, and is ultimately very tiring.