Starting with version 11.2, ASM runs from the Grid Infrastructure home in both single instance and cluster installs. This is very different to earlier versions so I would encourage you to invest some time in understanding the differences. Here is a quick overview of some of the more interesting features.
Integration of Oracle Clusterware (Cluster Ready Services) and ASM
Oracle Cluster Registry (OCR), voting disks and ASM spfile can now be stored in an ASM disk group. ASM instances, disk groups and other ASM related objects are now resources managed by Clusterware and stored in OCR.
ASM job role and user separation option
I have a separate post on that – please see ASM job role and user separation option.
ORACLE_BASE directory cannot be shared in cluster installs, but it can be shared in single instance installations.
No localconfig in single instance installs
Although localconfig utility is mentioned in 11.2 documentation, in the context of Cluster Synchronization Service (CSS) and host name change, there is no localconfig in 11.2. Instead we now have roothas.pl. For more info on this please see MOS Doc ID 986740.1.
ASM can be set up during the install or later with ASMCA
ASM Configuration Assistant (ASMCA), a new tool in 11.2, is used to create and configure ASM instances, disk groups, volumes and ASM Cluster File Systems (ACFS). ASMCA can be used in GUI and command line modes. In addition to that, a silent mode can be used to automate ASM setup.