well here's the deal...

1. getting in late, pisses everyone off... afterall if they can get their tired selves out of bed to be at work on time, so should you.

2. leaving late: no one likes a show off who's there after hours trying to prove that they work hard. just get there on time, get your stuff done and leave on time, just like everyone else. unless of course you're hte boss

3. leaving early: wtf dude.. if i have to stay here till 5:00pm sharp, then why the heck should you be any different. unless of course you got in substantially early, and you have an important appointment to get to, then that's a different story.

at my old office job, we had a coworker who strolled in every day at like 10 or 11 am, then left by 3 to go swimming or meet up with friends for drinks.. we all loathed him and secretly wished he got fired every single day... in the long run, best thing to do is get in on time, get ur work done, leave on time.
we had another person who got in every morning at 9:30, when we were there at like 8:30 because she liked going for a run on the beach in the morning . she'd stay late an hour each day, but we all knew she wasn't getting any work done in that last hour, it was more of just being there for hte sake of saying sh'es putting in her 8 hours. and when she'd come in late, of course the first hour would be just screwing around drinking her coffee and having her muffin...

period.