Tip: Use this instead:
```python
>>> now=datetime.datetime.utcnow()
>>> now
datetime.datetime(2013, 4, 26, 20, 43, 12, 398369)
>>> now.replace(minute=0, second=0, microsecond=0)
datetime.datetime(2013, 4, 26, 20, 0)
```
It's not much shorter but at least it doesn't create a new object. Also, if the original `now` had a timezone on it, it wouldn't be lost when doing it this way.