Prices are high, but should I sell my rental property?

[Gary Rutledge]

I own a rental house in a hot neighborhood in Dallas, Texas that was built in the early 1950's.  People are demolishing the older houses left and right here and putting up larger homes. Last year, the first home on my block was scraped and the newly built home sold for $945,000.  I can easily fill my little house with good tenants in about a week from putting out an ad.  Plumbing, electrical, AC, water heater, roof, windows have all been replaced so it is low-maintenance.  Also, I don't mind being a landlord.

I paid $88,000 for the house in 1998 but it is now worth about $275,000.  I no longer have a mortgage, so after property tax and insurance I clear $9,000 a year (Dallas taxes are quite high). 

The market in Dallas is really, really good right now so I feel as if I should sell.  But if I did sell, I'm also not sure what I would do with the cash that I'd be pocketing.

...Or perhaps I should hang on to it. It really has turned out to be an easy way to make an extra $9,000 a year.

Is there anyone in a similar predicament who might have some ideas? 

(A little about my situation...I am a 51 year old teacher, I live in a $200,000 home in which I still owe about $100,000 and should have that paid off in ten years. I will retire in 12 years.