I shoot on a D30 with a 24/2.8, 50/1.8, and 70-200/2.8. Indoor basketball is tough to get a very crisp shot without using a flash. With a flash, under the basket with either the 24 or 50, you can get some very good stuff. Best to use the flash lightly though -- otherwise the background is too dark.
Without a flash, 1.8 is definitely the preferred aperture; with 800 ISO you can crank up the shutter to 1/350-500, and even get down to 400 ISO in well lit gyms. At 2.8 you must shoot at 800 ISO (beyond that, at 1600 ISO, I find the D30 picture quality breaks down noticeably) to get a shutter speed of 200 or over. Anything less is subject to blur a good deal of the time. I've gotten some pretty good results at 2.8 with 200-250 shutter speed. For foul shots, for shots of the coach and the like, I will go to 125-160 and see if I can get the ISO down to 400. Works once in a while.
At 800 ISO, the pictures will be a little fuzzy. Shoot in RAW and try the Linear Sharpen Pekka has developed. Makes a significant difference in the quality of the photo.
Good luck! Let me know how it goes.