Compiled byTonya Vinas When it comes to motivating employees, go directly for the green. This is according to a recent e-mail survey by WorldatWork, formerly the American Compensation Assn. The professional association surveyed 630 members and found that spot bonuses -- cash rewards handed out immediately for outstanding work contributions -- are as significant an employee benefit these days as flexible work schedules, stock options, and work/life benefits. Fifty-percent of survey participants use spot bonuses, and 32% of those who don't use them say they plan to start. The bonuses are as high as $2,500 for some companies, and they are not limited to management ranks. Ninety-five percent of respondents make IT staff eligible for the bonuses, and 47% of those who have a spot-bonus program make it available to all employees.