According to Wikipedia, blog carnival is a type of blog event similar to a magazine, in that it is dedicated to a particular topic, and is published on a regular schedule, often weekly or monthly. Each edition of a blog carnival is in the form of a blog article that contains permalinks to other blog articles on the particular topic.
I think this could be an interesting way to improve our creativity. For example: If you join Skywatch Friday, then you have to try taking a photo which includes the sky, post that photo on your blog and put a link to this carnival starting each week on Thursday evening at 07.30 pm, GMT. I have seen some amazing skies, like at The Blog of Note "Quincy Daily Photo".
These are just a few carnivals I found for the week (you can search for a lot more on the Web):
I know this list here is way from perfect...
Menu Plan Monday What's on Your Menu This Week?
Monday's Movie Write about any movies, television or big screen, that you’ve seen over the past week and write about it.
Mellow Yellow Monday Post a photo with a little or a lot of yellow. Because life is better with a splash of yellow.
I Heart Faces All about faces according to a certain contest category.
Monochrome Maniacs Post a monochrome photo.
Blue Monday Post about something blue on your blog.
Music Monday Share your songs.
Monday Musings Post a quote on your blog.
Mojo Monday Just upload a project using the week's sketch.
Laughter Lives Tuesday A day when we all get to look forward to a good laugh. No rules, no stress, just OPEN SEASON FUNNY!
My World Tuesday Show others the area around you and become our Tourist Guide!
Sketch Tuesday Make your sketches and then send them in.
Tasty Tuesday Post a recipe or food according to the given topic.
Ruby Tuesday Got something RED that you've photographed?
Watery Wednesday It's that time of the week to pull up your watery photos.
Works for Me Wednesday Post a little tip you've learned on any (G-rated) topic--anything that has "worked for you" in making your life easier.
Thematic Photographic Every Wednesday evening at precisely 7 o'clock Eastern there will be a new Thematic Photographic entry.
ABC Wednesday If you have something to share, be it a photograph, piece of art or poetry according to the given alphabet.
Thrifty Green Thursday Starts every Wednesday at 8 p.m. PST. Write your own “thrifty green” tip on your blog.
Booking Through Thursday Post your answer to a given question about books and readings.
Sepia Scenes ANY photo that you've taken, but in SEPIA.
Thursday Thunk Interpret a given subject in any way you want.
Friday Ark Friday (plus or minus a few days) photos of chosen animals.
Hooked on Fridays Tell us what you’re hooked on today!
Photostory Friday Post photo(s) that YOU took and simply tell the story behind it. The shot doesn't have to be technically or creatively perfect; life isn't.
Skywatch Friday Photo which includes the sky.
Monochrome Friday Post a monochrome photo.
Postcard Friendship Friday Any type of postcard, a photo of a mailbox, mailman, a stamp image, postcard altered art, or simply a photo of something that you find 'Postcard Perfect' etc etc etc!
Share a Smile Saturday Find your "Smile" throughout the week and schedule it to post on Saturday.
Living Simple Saturdays Write about your own journey towards simplicity. What does simplicity mean to you?
Shutterday The photo challenge for saturday
Photo Hunt Post a photo from your personal collection that best represents the theme.
Scenic Sunday Photo meme of the scenery. It can be landscapes, buildings, flowers, or anything you feel is a scenery photo.
Today's Flowers Open on every Sunday at 18:00 - GMT
Yummy Sunday Food shots... any food will do whether you cooked it, your sister did, your hubby did, or even the food you had at a restaurant. There is no theme. So you can post any food at any style you want.
Sunday Scribblings Create a piece of writing inspired by a specific writing prompt.
Simply Delicious Sunday Recipe from newspapers, magazines, old maiden aunts, grandmothers, friends and every potluck you ever went to and said I have to have that recipe!
Smiley Sunday Share to the whole world WHAT or WHO made you smile (or laugh) the past week.
The Garage Your daily dose of automotive (Well, it isn't really set for Sunday but enjoy).
Let me know if you know about other blog carnivals through the week.
PS. I just found A Daily Meme, while searching for another smile meme. It is an easy spot to find some memes to blog about... I think it is a great archive. There are quite a lot of choices you may like.