Depends on if you need it installed before your phone was lost. If you have already lost your phone and have nothing installed then Plan B is the only answer.
If you have your phone then just using Latitude alone recovered my stolen Droid....Where's my droid is also good...as is Wavesecure. I have all the above installed on my phone.....what can I say....I believe in redundancy.
Plan B is ONLY to be used AFTER your phone was stolen.