When I was in management in our business of about 75 employees, we converted to a safe harbor 401k plan. We do not provide a "match" but contribute through our 401k/profit sharing plan a minimum of 3% of an employee's wages and going up to a high of 14.5% depending on age and length of service for non-lawyer employees. This enables us to put up to 14.5% pretax in the shareholder's pockets so most shareholder's can max out the plan. Which, if you are 50 and over, is $49,000 for 2006 and $44,000 if you are less than 50.
We don't pay the contribution until year end because it is a profit sharing contribution and we could decide to forgo or reduce the contributions. We never have made less than the maximum. The money doesn't actually hit employee accounts until early February because of the plan testing we have to do.
Employee voluntary contributions are sent to the plan immediately when made.
Before I went part time I tended to front load my voluntary contributions early in the year. Now I do the reverse.