There may come a time when you just can't face purling another row; in fact, some folks will seek out garter stitch patterns expressly so they don't have to deal with repetitive purling.
That's the time to consider backwards knitting. A row that is knit backwards comes out looking exactly as if it had been purled. Here's how it works.
Instead of purling a row by working stitches from the left needle onto the right:
1. Turn work so all stitches are on right needle.
2. Holding yarn to back of work, insert tip of left needle into front loop of first stitch on right
needle, coming from back of loop toward the front (from left toward right of that loop).
Left needle will ride above right needle; tip of left needle will exit loop in a position
between first and second stitches on right needle.
3. With right needle, draw yarn through loop, creating a new stitch.
4. Slip new stitch onto left needle.
5. Repeat steps 2 through 4.
This method is a little slower than purling, but it produces exactly the same results. Keep it in your bag of tricks.