Well, good news that you made the grade. What a stupid way to go about hiring someone! I'd make damn sure you go to as many interviews as possible over the next 2 weeks, make sure the agency knows you're actively pushing for more interviews and not putting your life on hold while they waste 2 weeks. You never know, something better might come along.
It'd serve them right if you got snapped up by someone else in the meanwhile. 
Kevin
That would be the ideal situation

I had the pleasure of doing nearly the same a few years back.....
Went to work for a company as an IT contractor.....i knew the first week was a trial week......but was gobsmacked when the 1st week was up got told by the IT manager that ok weeks up......were taking on another IT contractor next week to compare, therefore you dont need to come in next week (which means unpaid for a contractor)......Agency rang me the following wednesday saying can you go back in immediately, they want you......I told the agency to stuff it

However agency kept phoning me back, so after insisting an increase in hourly rate and insisting i couldnt start back until the monday (even tho i didnt have anything on) I went back on the Monday.
But that gave me great pleasure in basically saying....."P1$$ me about and I'll do the same to you"

Could be a good basis do to the same (ie increase in salary....as you've been offered another job (small white lie maybe

)
Depends how brave you feel and how much you want this job
