When you get to Amarillo, old 66 runs along Amarillo Boulevard, north of I-40 for a while (this is now the lousiest part of town, where the Junior Jaycee-ettes will wave to welcome you and hotels/motels rent by the hour), then dips down south on Georgia/McMasters to 6th street , Antique Store Alley as it's known. (If you hit town during a weekday, Barnaby's Beanery has good eats, open at lunch.) It runs back into Amarillo Boulevard at Bell, but ends shortly afterwards without much of interest, and it might be better to take Bell back to I-40 at that point. Down the road in Vega, there's still the old Route 66 Motel and Restaurant, visited by Route 66 nostalgia buffs. Most of 66 in the Texas panhandle countryside is actually the access road to I-40, though, so you are or aren't on it if you're using I-40, depending on your attitude.

In New Mexico, I think you can still pick up 66 in Tucumcari and follow it for a bit. I'll have to check...

Sarah