Question : What is the best way to partition storage for Exchange 2007 for a small business?

We are purchasing a new Dell PowerEdge 2950 to migrate our Exchange 2003 system to Exchange 2007 and we need advice on the best way to partition storage given the drive configuration we're getting.  The Mailbox, Hub Transport, and Client Access roles will be installed on a single box.  Our user base is expected to grow from about 60 to about 100 over the next few years.  The server will have 6 drives, 2 x 73gb and 4 x 146gb.  Our options are to create 3 RAID 1 partitions (one 73gb for OS, one 146gb for Data and one 146gb for Logs), or a RAID 1 for the OS, and a RAID 10 for Data and Logs.   Which is better - separate RAID 1 spindles for data and logs or the better performance of the RAID 10 with both Data and Logs on the same spindle?

Answer : What is the best way to partition storage for Exchange 2007 for a small business?

Based on that, I would go with what i have written above.
The only other thing you might want to consider is three mirrors.

2 x OS
2 x Logs
2 x Databases

Your total databases are 64gb so you would use around half of the capacity available.
As it is Exchange 2007, you might want to think about splitting the users over two databases, see if you can get them down to around 30gb each. That would allow you to go to 100gb total and still have space for recovery.

Simon.