6061 is widely used for construction of aircraft structures, such as wings and fuselages, more commonly in homebuilt aircraft than commercial or military aircraft.
6061 is used for yacht construction, including small utility boats.[8]
6061 is used in SCUBA
tanks (post 1995)
6061 was the material used for the Pioneer plaques.
6061-T6 is used in many fly fishing reels.
6061 T6 along with 7075 aluminium alloy is frequently used in the secondary chambers and baffle systems in firearm sound suppressors
The Pioneer plaques are made out of this same material, that's pretty cool

(if its good enough for aliens
Thanks for a good excuse to learn something new!