Below are some places/activities that I visited/did on weekends:
1) Rodeo @ Reliant Park
It is held on every day of March where Reliant stadium will be fully seated by people from Texas and other states to watch the Bull Riding, Steer Wrestling, Bareback Riding and many more. It's very good! USD16 for the cheapest seat + USD60 return by cab.
2) Houston Museum of Natural Science @ Hermann Park
It's a good museum. This is my first time seeing a place named museum to be very crowded. USD15 for Main Exhibition Halls + USD10 for 3D show + USD30 return by cab
3) NASA Johnson Space Center
There is a 50-min tram tour where you can see closer the NASA building and facilities and got opportunity to enter their real space training center. But, the exhibition hall is quite disappointing. Not many exhibits plus, they are fake. If you wanna come here, don't put too high expectations. But overall, it is a worth visit. USD20 + 20 miles away.
4) Galveston Island
Mmmm...Not much you can do there especially after the big cyclone last year.
5) Houston Zoo @ Hermann Park
It's a very good zoo. The way they display the animals especially at the primates and wild area is something to follow. There is also a quite big park to relax. USD10 + USD40 return by cab (Quite close to the Museum but this time, the taxi driver took a longer route).
6) Basketball Game @ Toyota Center
April is the month of Basketball and Baseball. My friends & I managed to watch a final home game between Houston Rockets (2x NBA Champion) vs a team from New Orleans. It was a great match. Yao Ming (one of the tallest people in the World) from China is in that team. USD25 for the second highest seat @ eBay.
7) BBQ @ Memorial Park
The park is very huge and purposely designed for barbeque area. We held a small BBQ party since we are going home soon (before we know our stay is extended). Plus, no more interesting places to visit.
Mmmm..overall Houston is quite a good city to live in but, it got a problem of public transportation....If you happen to come here, please do not use bus outside the uptown area...It happened to me at Wheeler station (South downtown) when someone insulted my friends and I with a lot of bad statements. We get out from the bus to avoid anything bad happen and the guy loudly shouted, "Yeah, you get out now!"
(i'll add some more soon...wanna pick some lunch) hope soooo...