I bought my first Roomba a little over a year ago. Named him "Jack" -- the son I never had. A few weeks back, in honor of National Poetry Month, I purchased and named his sister, "Jill." Neither Jack nor Jill has fallen down any hills (or flights of stairs) yet, however, and their maker, Motley Fool Rule Breakers recommendation iRobot (Nasdaq: IRBT), didn't take a tumble yesterday either.

To the contrary. First-quarter 2010 results out of iRobot stunned the company's critics as the company reported 67% revenue growth and a earnings surged from a $0.07 per share loss a year ago to a $0.24 profit during the first quarter.

How'd they do that?
iRobot blasted Street estimates completely out of the water yesterday, and it did this with a two-pronged attack. International sales for the quarter more than doubled, and exceeded domestic sales here in the U.S. where iRobot sells through a strong retail channel -- including outlets as diverse as Sears, Bed, Bath & Beyond, and Best Buy -- by more than two times.

Meanwhile, the company's "government & industrial" sales (a politically correct euphemism for what they really are, warbots) posted a nearly-as-stellar 76% year-over-year growth. Apparently, iRobot's still has little competition here from rival warbot-maker General Dynamics (NYSE: GD), whereas its partnerships with Deere (NYSE: DE) and Boeing (NYSE: BA) are doing just fine.

More numbers: Gross margin was up. (Six percentage points, to 35%). And with "visibility" improving, full year guidance also looks strong. ($375 million to $385 million for the year, with $0.35 to $0.40 per share in profit.) And accordingly, the shares are way, way up -- 32% as of this writing.

So up, up, up -- was anything down?
Actually, yes. iRobot had three bits of "down" news: two good, and one bad. Despite surprisingly strong sales, iRobot's inventories and accounts receivable both dropped slightly in comparison to the year-ago quarter, suggesting that iRobot's CFO continues to focus like a laser on good management of working capital. The strange thing is that, somehow, free cash flow for the quarter declined -- dropping to just $8.5 million, a striking 37% drop year over year.

Still, this leaves iRobot with $30.5 million in the cash-collection kitty for the past 12 months, plumping out its warchest to a fat $85 million in cash and equivalents. At a market cap of only 16 times free cash flow, and Wall Street still projecting 20% growth for the company, that seems a mighty fine price to me.

Are you on the hunt for growth stocks selling for reasonable prices? We've got 'em right here.

Fool contributor Rich Smith owns shares of iRobot. Best Buy and General Dynamics are Motley Fool Inside Value choices. iRobot is a Motley Fool Rule Breakers recommendation. Bed Bath & Beyond and Best Buy are Motley Fool Stock Advisor picks. The Fool owns shares of Best Buy. The Fool has a disclosure policy.