who says lanky is an insult? it's a compliment. most models are lanky: tall and skinny. a lanky walk, run, or dance is the best thing you could see. lanky peoplerock. most of them are really cool. lanky people look good in almost anything too and they could get away with anything they wear. they are on top of the world and everyone looks up to them :)
a lanky-wannabe: hey im lanky (tries to run like a lanky person)
a real lanky person: hey guys! (runs so "lankily")
Definitely not neccesarily an insult, although like most words it can be used as one if the low-life insulting another person is that stupid. Mostly used as an amusing comment or nickname. Disproportionately tall and thin, especially referring to long arms and legs.