I am reluctant to even post this, but here goes.
There is a way to get your UCI without waiting for PER.
This will be useful for those of you who have never applied for a Canadian visa before and have no UCI to check your ECAS status (like me).
I just called up the standard CIC service center, waited on hold for a while (about 15 minutes), and asked the agent for my UCI. After confirming some personal details, she gave me my UCI. I was able to use it to log into ECAS and check my status, even though I have not yet received the PER e-mail.
Some people have said the CIC number doesn't work outside of Canada. It does, it's just not free like it is from within Canada or the USA. You'll be paying the standard rate your provider charges for calls to Canada. Some people also have said CIC won't give you your UCI or a phone update on your application. They might, if you are friendly and get the right agent. I didn't ask about the status of my application because I know they'd tell me the same thing that I can see in ECAS.
Please, PLEASE, PLEASE don't flood CIC with calls. Remember, payments are charged soon after the envelopes are opened. Right now, they are working on May 7, 8 and 9 applications, so anything later than that is sitting in a stack somewhere and hasn't been opened so there will be no UCI assigned. This is really only useful for people whose application date has begun charging, so they can see their status between that time and the time of receiving PER. If you submitted your application sometime in June or July or even the second week of May it hasn't been opened and hasn't been assigned a UCI so PLEASE don't send a tidal wave of calls to CIC. That is why I hesitated to post this at all.
Use this information responsibly and respectfully.