Code tag ([CODE.]...[/CODE.]) is now a real problem. We should be able to solve this problem by disscussing it here. Here are some solutions disscussed up to now (which I remember):
Code:
S1- Code tag script which will only notify you that your post has some not tagged code.
S2- Auto code tagger (which is the best I think).
S3- Code tag button.
S4- Code tag warning pop-up for newbies.
S5- Forcing code tag for people with less than a number of posts.
S6- Hiring somebody to add code tags for newbies.
S2 and S4 are good I think.

Please send your ideas here.
Most important it needs especial attention of admins.