Hydroseeding is a great alternative to sod.  There are pros and cons to each.  The biggest benefit of hydroseeding is the cost.  Hydroseeding is usually about a quarter the cost of getting sod installed.  The biggest downside to hydroseeding is you must have a little patience.  It takes a few weeks to the seed to germinate but you are usually mowing after 4 to 6 weeks.  However, even with sod you need to stay off the lawn for a few weeks.  Here are some photos from a few jobs we have done the past few days.