Readily.
Southwest Airlines has a dozen or so flights a day between Reno and Las Vegas, beginning at around 6:30 a.m. and going till around 9:30 p.m. It's 450 miles or so and takes 75 minutes gate-to-gate on a good day.
We've seen online promotional fares as low as $98 round-trip, though online full fares are usually $230 (without the 20% or so in taxes and fees).
You can almost always find a seat on a flight between the two gambling cities, though commuter times in the mornings (especially Mondays) and evenings (especially Fridays) are generally packed, so book as far in advance as you can for availability and best price. Go to www.southwest.com for the complete schedule and range of fares.
Other than that, your pickin's are mighty slim. America West flies once or twice a day non-stop between Reno and Vegas (they have several other flights, but you have to go through Phoenix); online fares are generally in the $130-$270 range.
