(Tip:  To report spam, follow @spam on Twitter and then direct message the @username – e..g., “d spam @spammer”)

You @-reply people you don’t follow with links.

You still have the default avatar (Hint to anyone who hasn’t yet)

You have been suspended on a regular basis: “Sorry, the account you were headed to has been suspended due to strange activity. Mosey along now, nothing to see here.”

You have one update, yet you add 100 people to your follow list every day.

You repeat your same tweet w/ blog post several times a day, and freely admit that it wasn’t a technical glitch on the part of your Twitter client.

Shamwow

Your followers count is in the single digits, but you’re following 100-1000 people.

Your URL goes to a horribly ugly site with black and red bold sans-serif text, sporadic yellow highlights, occasional ALL CAPS and exclamation POINTS on a white background!!!

You URL has a video of you pulling $2,000 cash.

You are following nor followed by anyone, and regularly send @reply messages advertising your product.

You follow people at random and drop them as soon as they’re following you.

You have a “system” for making lots of money.

Automatic direct messages with links to new followers.

“Be-a-magpie”

Your “name” associated with your Twitter ID consists of a 6-letter combo of the letters a-s-d-f.

All @replies.

No status updates.

No profile, url, default background…

1. There is a bird-chirping noise coming from your computer every minute or so.
2. You refer to people as @nickname outside of Twitter (seek help if you refer to them that way in real life)
3. People have threatened to un-friend you on Facebook because you have the Twitter app turned on.
4. You can name more than 5 URL shorteners (and TinyURL is not one of them).
5. You have written your own script or program to retrieve tweets.
6. You see nothing wrong with divulging intimate details of your daily life to 100 or more complete strangers.
7. You actively check friendorfollow to see who isn’t following you back.
8. You qualify every sentence with at least one ‘#’.
9. “It’s complicated,” means that you need 141 characters to tell the story–even after shortening everything to txt abbreviations.
10. You subscribe to news outlets and blogs that feed to Twitter because using an RSS reader is just too much work.
11. You have linked rememberthemilk, Google calendar, etc. to your Twitter account.
12. You check Twitter in more than 3 ways in the span of an hour (txt, m.twitter.com, Tweetdeck, website…)
13. You see an unfamiliar “from …” Twitter application or service on someone’s tweet and stop everything to check out that application.
14. You are obsessed with maintaining your Twitter grade or TwitterRank.
15. You take Tweetwasters as a personal challenge.
16. You make a point to say good morning and good night to all of your followers.
17. Most of your nouns begin with “tw” (i.e., tweeple)
18. You tweet from the jacuzzi (from @cheapwebmonkey)
    
19. You tweet while cleaning the toilets (from @runkerrierun and @runnergoslow)

More lists:

• 16 ways to know you are addicted to Twitter
• 5 signs that you’re addicted to Twitter
• Top 10: Signs You’re Addicted to Twitter or Friendfeed