I've seen this little short on the Sundance Channel in the US a couple of times, and it's very funny and insightful, and certainly well worth 13 minutes of your time.
And if you're an American, think of the title as "Caller ID". This short takes place in the UK, and apparently over there they call the service which identifies phone numbers "Call Register".
I won't go into detail on the plot since I've submitted a plot outline and summary for this short. The whole short shows the two male friends sitting together on couch talking, and then a split screen appears when there's a phone call between one of them and the girl. So... the film is all dialogue, but what great dialogue! In a short amount of time, this film manages to touch on quite a number of nerves about feelings which deal with asking for dates, friendship, relationships, and the mechanics of it all in the age of cell/mobile phones and caller ID. The triumphant feeling a guy has when the girl says yes, the sour grapes feeling when she says no, the awkward feeling of dating someone your friend has dated, the mixed feelings associated with previous relationships, the insecure feeling caused by having a better looking friend or trying to date an attractive girl, the gloating feeling when outdoing someone superior to yourself, and the overthinking associated with all these feelings are seen here.
And as for the phone mechanics, we see much of the modern nonsense like not wanting to use caller ID block because it makes you look like a stalker or solicitor, wanting the option to call and hang up but using a different phone so that you aren't identified as the person who did it, lying about calling and hanging up, lying about "accidently" dialing a number, not deleting an ex's number from your phone, or deleting it but using your handwritten phonebook to look up who called, etc. Ugh... reminds me that I wish I had lived before the age of telephones.
Overall... quite funny and painful at the same time. If you've ever been the awkward average guy calling a guy for a date (and I have), then this short is for you.