Buy a switch adapter for the outlet (accepts one cord, has a switch on top). You still have to reach for the outlet, but there's no plugging/unplugging.

http://www.acehardwareoutlet.com/(rj1dxhalzhtnwc55i1r23e55)/ProductDetails.aspx?SKU=3189842

there are extension cords out there that have switches on them, i have a couple ikea lamps plugged into one with a foot switch.

I installed two Knappa lamps to one switch for bedroom accent lighting.

I installed a electrical box with a round white cover plate in the ceiling. I then drilled a hole in the center of the cover plate and ran the cable inside and hardwired the lamp. I would suggest a cable clamp mounted to the wire underneath the cover plate to make adjustments on the height of the lamp location.

Hope this helps.

-Extreme DIY-

I installed two Knappa lamps to one switch for bedroom accent lighting.

I installed a electrical box with a round white cover plate in the ceiling. I then drilled a hole in the center of the cover plate and ran the cable inside and hardwired the lamp. I would suggest a cable clamp mounted to the wire underneath the cover plate to make adjustments on the height of the lamp location.

Hope this helps.

you might want to try this:
http://www.seenontvproducts.net/zapperadapter/index.html

i used to have something similar at home. it was an adaptor that screwed into a light bulb socket and had a little chain that you could just pull to click the light on and off.

Along the same line as frannybee's suggestion you can use something like this remote wireless switch.

What I've done with mine, is use ikea dimmer cord and attached it to my wall using command performance strips, and viola instant light switch.

I just bought the $7.99 dimmer switch/cord at ikea.

I have those for a few lamps.

I just finished hardwiring mine to replace the dated brass chandelier over my dining room table and am feeling extremely awesome right now. It was actually pretty easy!

We hardwired ours to the existing box for an old dining room light. Piece of cake. Just be sure to turn off the power.
http://farm3.static.flickr.com/2042/2393281026_2ca8d768f6_o.jpg

Other than that, it looks like you've received tons of good advice for adding an in-line switch.

IKEA dimmers are a ripoff.

With every single one I've ever bought from them - after the lightbulb burns out, so does the dimmer switch.

I'd use the Lutron dimmer switch on a cord.

http://www.walgreens.com/store/product.jsp?id=prod3498235&CATID=100416&skuid=sku3497078&V=G&ec=frgl_559301&ci_src=14110944&ci_sku=sku3497078#

Any hardware store will have switches that you can install on the cord. It is super easy, and will take all of six minutes.

just buy the socket-and-cord from Urban Outfitters ($14) or World Market ($12.99) instead of from Ikea. It will have a switch installed on the cord. World Market's come in several colors, including clear, which I use with my Tord Boontje garland light. It works beautifully.

Is hardwiring a pendant lamp to an exisiting light socket something that is relatively easy to do? I've been wanting to do this for awhile, but don't know how. Any helpful links or DIY instructions out there?

You can also hook them up to a Clapper. (Yes, they still make those! :) )

I would like to wire-in a Knappa to replace an existing ceiling light fixture. I was trying to find out if this is possible—apparently it is. Pointers to instructions would be much appreciated. Thanks.

I found instructions for wiring-in the lamp here: http://grassrootsmodern.com/2007/12/20/knappa-pendant/

Question: is it a problem (i.e., potential hazard) that there is no ground wire?

I don't understand this, but it seems relevant:

http://wiki.answers.com/Q/What_to_do_with_ground_wire_in_wall_when_wiring_metal_light_fixture_without_ground_wire_into_plastic_outlet_box_with_ground_wire_Basically_wall_has_3_wires_fixture_has_2_and_no_place_to_ground_to.

We posted a tutorial on how to hardwire the Knappa or any other plug-in light on our blog:
http://www.ourlittlebeehive.com/2011/01/tutorial-hardwiring-plug-in-light-for.html

Alternatively you can put an in-line switch on the cord. Home Depot has then in the electric department.