SpongeBob
Invitations
A cool SpongeBob invitation is the pineapple-in-the-ocean invitation.
Cut a piece of
yellow tag board in the shape of a pineapple. It has to fit exactly
inside a snack-size Ziploc bag. On the front of the tag board write
something like: "Who lives in a pineapple under the Sea?",
and then on the back you can write: "Sponge Bob Square Pants!
He wants you to come, and party with me!" Underneath can be your
kids name, your address (add "Bikini Bottom" to the address),
Cast-off (date), Dive time (start time), Resurface (end time), and
"SEA you soon!!".
In each bag place
a small amount of sand, some sea-life confetti, small shells, etc.
Seal them up and place them in envelopes (preferably blue). If you
want to take this idea to a higher level (and the invitations will
be hand delivered), after writing, laminate the tag board to ensure
that it's waterproof. Then float it in a the zip-lock bag that's filled
halfway with water and blue food coloring, some sand and small shells.
You can then glue a fridge magnet onto the bags for the guests to
put on their refrigerator.
Another one of
the coolest SpongeBob kid party ideas for an invitation is to get
some of that flat sponge that puffs up when immersed in water and
cut rectangular strips. Then with permanent markers decorate one side
of the sponge to look like Spongebob. On the back of the sponge (with
a fine-line Sharpie or any other permanent marker), write the details
of the party (name, address, RSVP #, etc.) Write "put me in water"
at the bottom. Having them actually soak their invitation in water
is one of those kid party ideas the kids just love!
If you're not
up to making the invitations yourself, take a look at these ready-made
SpongeBob invitations and thank you notes.
Decorations
The SpongeBob theme provides for fun kid party ideas for decorations
you can make on your own.
Hang a sign on
your front door that says "Bikini Bottom" (this is the city
where SpongeBob and his friends live). You can also make a sign that
says "The Krusty Krab" (SpongeBob is a fry cook there) and
hang it in netting. You can also put up this cool SpongeBob banner.
From brown bulletin
board paper (or a refrigerator box), cut out the shape of the underneath
of a boat and hang it on the ceiling. Hang a poster-board anchor tied
to a rope from the boat. Also, hang a fishing pole from the boat's
side with a fishing line and a plastic worm dangling from it.
To create the
ultimate Bikini Bottom setting hang teal, royal blue, sea-green and
light blue crepe paper streamers of varying lengths from the ceiling
to create the effect of being under the sea (you can glue cut-out
fish to the ends and middles of these strips). Also hang fishnets
and on them hang fish cutouts and various sea-life creatures. In the
doorways hang long green paper streamers for seaweed. You can also
hang them from a clear fishing line to appear as if they're swimming
around.
Don't forget to
hang jellyfish made from half-cut paper plates with streamers attached
to resemble tentacles, and sprinkle various SpongeBob accessories
your kid may have.
Then, add some
goofy items that pay tribute to the whit, whimsy wackiness of the
world of Sponge Bob and friends. Add a giant tissue pineapple, tiki
masks, surfboard standees (you can make from cardboard), and even
a few white brief-style undies!! Feel free to go crazy with these
fun SpongeBob kid party ideas.
Get a few rolls
of brown paper (the kind used in houses that are under construction)
and place it on the floor to give the appearance of a sandy ocean
floor. Also, place lots of blue-shaded balloons on the floor to create
an ocean effect. You can put towels all around and disperse all kinds
of sand toys.
On the tables,
put a blue tablecloth with green strips across and hanging down from
the edges (for seaweed). You can add fish to the end of each strip.
Seashells can be used as table confetti and you can also cover the
tablecloth with fish net or use this SpongeBob tablecover.
Tie napkins with shell necklaces or glitter jelly bracelets.Use this
SpongeBob centerpiece or get some real pineapples. Take each one,
cut a few inches off the bottom so that it has a flat edge to stand
on, then cut out two squares and a rectangle from light blue construction
paper and glue them onto the pineapple as two windows and a door.
Bubbles always
make for fun kid party ideas, especially for the SpongeBob theme.
Get lots of bubble bottles and bubble guns (or if you really want
to go wild - this awesome and inexpensive bubble-blowing machine)
and blow bubbles across the room while you watch the kids race around
trying to pop them.
More
Ideas 
