Fernando Alonso on top in Second Friday practice.
Button agrees to stay at Honda for 2009.
Modifications begin on turn 10.
New digital flag system to debut in Singapore.
Pos Driver Team Time Laps
1. Alonso Renault (B) 1:45.654 30
2. Hamilton McLaren-Mercedes (B) 1:45.752 + 0.098 28
3. Massa Ferrari (B) 1:45.793 + 0.139 31
4. Kovalainen McLaren-Mercedes (B) 1:45.797 + 0.143 31
5. Rosberg Williams-Toyota (B) 1:46.164 + 0.510 34
6. Kubica BMW Sauber (B) 1:46.384 + 0.730 36
7. Raikkonen Ferrari (B) 1:46.580 + 0.926 25
8. Button Honda (B) 1:46.901 + 1.247 32
9. Nakajima Williams-Toyota (B) 1:47.013 + 1.359 32
10. Glock Toyota (B) 1:47.046 + 1.392 22
11. Webber Red Bull-Renault (B) 1:47.137 + 1.483 15
12. Piquet Renault (B) 1:47.145 + 1.491 35
13. Vettel Toro Rosso-Ferrari (B) 1:47.300 + 1.646 33
14. Bourdais Toro Rosso-Ferrari (B) 1:47.487 + 1.833 24
15. Coulthard Red Bull-Renault (B) 1:47.640 + 1.986 31
16. Heidfeld BMW Sauber (B) 1:47.760 + 2.106 36
17. Fisichella Force India-Ferrari (B) 1:47.965 + 2.311 12
18. Barrichello Honda (B) 1:48.009 + 2.355 25
19. Trulli Toyota (B) 1:48.059 + 2.405 28
20. Sutil Force India-Ferrari (B) 1:48.311 + 2.657 36