Oh, dear — Silicon Valley VCs acting like teenage girls.

And there’s not even a hot start-up in sight to chase and scream over.

It must be the holidays and First Round Capital’s annual digital greeting card, which is based on one of the popular viral videos of the year.

In 2008, First Round did its own version of “Dancing Matt.” In 2009, the firm’s CEOs sang as if they were Susan Boyle in “I Dreamed a Dream.” And last year, it was partner Josh Kopelman wearing a body suit to mimic the Old Spice guy.

This year, it spoofs one of the more irksome music videos of 2011 — Rebecca Black’s “Friday.”

I like First Round’s version a lot better.

Along with the rhythm-impaired VCs, you can see a wide range of their start-ups here, such as Xobni, Path and — thank goodness, since they can sing — Birchbox.

Enjoy:

And I thought I was the only one who was incredibly irritated by the latest YouTube sensation, Rebecca Black, and her profoundly grating “Friday” music video.

Not so!

So are a bunch of kids interviewed by the Fine Brothers for their “Kids React to Viral Videos” series.

The young folks pretty much say it all:

BoomTown promised a Yahoo internal memo upon our return from vacation today and we will not let you down.

Thus, here’s a doozie Yahoo (YHOO) CEO Carol Bartz recently sent to her troops.

It’s actually from mid-August, although it took me this long to get my hands on it, as people at the company are justifiably a little memo-leaking shy after this missive that complains of the sugar-low mood of the staff.

One in a series of weekly Friday communications from her, some of which I have posted before, this one got a lot of attention internally, especially among the down-in-the-dumps engineering staff, who were less than pleased with the damn-the-torpedoes-stop-yer-whining tone of the memo.

Whatever the reaction, it is certainly a classic Bartz times 10–a definite back of the hand for those Yahoos who perhaps dwelled too much on whether or not they liked the recent search deal she struck with Microsoft (MSFT).

Here’s the basic gist of it: Fie on naysayers, stop bellyaching, Yahoo rocks and get back to work!

And here’s the memo–referencing the tough week, her knee surgery and the need to focus, people!!!–with the email address section omitted:

I’ve had one! All the work, all the explaining, all the opinions!

I wanted to crawl into a hole and eat chocolate (and of course my knee boo-boo made me feel even sorrier for myself). Making the search decision and driving this much change for us was hard, but it is done.

So I am out of the hole, ready to attack the future. We are Yahoo! 581 MILLION PEOPLE came to us last month. Our audience increased 1.9% month-over-month, faster than the overall Internet population (1.2%).

Our job is to keep growing that audience with a great homepage, great media properties, great communications products and a great search experience. Match that with a compelling advertiser program and voila! We are the largest media property on the Internet.

So get out of the sugar low–we have work to do. Stop staring at our navels, stop arguing with each other. Stop debate, debate, debate, and let’s focus on the competition.

Let’s focus on a great Yahoo! Our average user is just trying to get through the day…looking to find out what’s going on in the big world and their own world. They want their Internet site to be great, and to work. They don’t care about how or about deals. They care that we are a trusted dependable site.

That is our simple mission. Focus on it!!!

My time-killing suggestion for the day: AdWeek’s “AdFreak” blog, which is packed with TV ads you probably haven’t seen. Did you know, for instance, that the Kool-Aid man was back?

Or perhaps you’ve wondered what a North Korean beer ad looks like (though honestly, you don’t need to go the full two-and-a-half minutes on this one; 20 seconds is fine):

Or maybe you want to see a guy doing a backflip in a wheelchair, as in this spot for Howstuffworks.com:

One word of warning: Don’t bother with the “Eat Canadian” ad, which is earnest and dull. Save that for Monday, as you’re easing into the week. Enjoy your weekend!