Citrusy cocktails like margaritas and salty dogs are served with a rim of salt, so although it shouldn't seem so odd to drink a salty limeade, I was fairly repelled the first time I tried it in Thailand. (I wasn't warned that it was salted beforehand, which didn't help.) Now, though, I like the interplay of sour, sweet and salty, which is especially refreshing after a long hike or other sweaty activity.
Alternatively, you could treat your limeade like a margarita and dip the rim of the glass in salt, or a combination of sugar and salt, before filling it.
Do you ever add salt to your lemonade or limeade?