This falls under the suggestion of blocking images posted from other users with posts, which you can do via your browser. This isn't something planned to be added here due to the way posts are pre-generated and cached.
If, however, you'd like an option to not show smileys for your own posts, you can already do so if you click Preview Post on your posts/replies, and check the Disable Emoticons checkbox.
Also, if maybe the actual suggestion is you want
betteremoticons, I'm always open to changing out the entire set, but it'd require someone creating one from scratch. If someone is so inclined or interested, definitely let me know.

edit: You can use this css to hide them on posts if you want to add it to a user-side setting (script, etc): .upc img[alt]{display:none}