The OP asked about a no-weld (solder) solutions, but Sparr is correct, you will need to do a bit of soldering. But once you solder the header pins in, you can use the DigiSpark in a breadboard without any further soldering.
Since a picture is worth a thousand words (and since I have the "gift-o-gab"

):

Solder the male headers in like this (a strip of six pins soldered to the I/O pins and two pins to the 5V & Gnd [not the Vin] power pins).
Then when you plug it into a breadboard, you have the pins neatly arranged like this:

Notice how the two power header pins line up to plug into the
+ and
- power rails, and the I/O header pins plug in to the component holes on the breadboard? That makes it easier to hook up circuits to the DigiSpark.
You can also use an additional LED, and resistor, to provide a pilot indicator to let you know when your board is powered, like this:

Just place the DigiSpark just to the right of the pilot light circuit. I also like to use a bit of hot-glue, or other glue, to hold down the LED and resistor to make this a bit more permanent on my dev board systems. (Just remember that this will draw a bit of power, so you will want to eliminate this when using circuits that draw a lot of power, or when using batteries, and you need to keep the circuit running for max time.) (EDIT: Of course, the DigiSpark does have its own pilot light, so maybe you don't want to put this into your dev kit, but it is still useful for other dev kits.)
If you would like more information about breadboards, and tips on how to use them, you can take a look at my "What is a Breadboard" page at:
http://projects.granzeier.com/what-is-a-breadboard/ (I hope that this is not taken as spam, but I do have some useful info there.)