As many of us do but if your time card actully shows that the company you work for can get in deep doo doo.
Luckily,our time cards and invoices don't actually show times, just hours. If I'm on the same job all day (rarely happens) my paperwork just says "8hrs". No one will ever know if I worked 7:00-12:00, lunch, 12:30-3:30 or just 7:00-3:00.
Our construction jobs are pretty strict about breaks and lunch, but they have multiple guys on the job. As a service guy I work alone so no one really cares as long as my work gets done. I turn in 8 hours worth of slips everyday, that's all they care.
Depending on where, what, how many different jobs I do that day, my actual hours could be:
7:00-3:00, no lunch = 8hrs
7:00-3:30, 1/2 hr lunch = 8hrs
7:00-3:00, 1 hr lunch = 8hrs:whistling2

not often, but I'd be lying if I said it never happens)
It depends on the job. As long as my slips total 8 hrs, the office doesn't care.