predicament: emoticon punctuation

when using an emoticon at the end of a sentence, do you still use proper punctuation before preceding on to the next sentence? do you just assume that you cannot use an emoticon in the middle of a sentence in between clauses?

e.g.:

• i'm so fat :). do you like churros :p?
• my cat hates me :/, but my hamster hates me even more :(.
• lean pockets make the world the move faster =o)!

and in the case of an ellipses, it could get really confusing. i mean, are you crying or what??

e.g.:

• carson daly sucks =(...ryan seacrest might be worse.

do not tell me that asian emoticons are the solution to the problem because they are vertical. as far as i'm concerned, ^_^ can go screw themselves.

also, i would've used the word conundrum instead of predicament in the title because i think it's more appropriate, but that would be so "garden state-y" of me!