Save result of sp_who in a table with inserted date

All,

I created a table that matches the structure of sp_who:

table tbl_sp_who:
  spid            smallint,
  ecid            smallint,
  status            nchar(30),
  loginame            nchar(128),
  hostname      nchar(128),
  blk            char(5),
  dbname            nchar(128),
  cmd            nchar(16)

When you execute the below insert statement:
insert into tbl_sp_who execute sp_who

It saves the result into the table...

NOW, I want to add a column "insertDate" where when a record goes in, it has a time stamp of when it goes it.  This way I can look at the table like a log.

How do I do it?  I tried adding the extra column and going the 'getDate()' route but just adding the extra column crashes the insert statement.  

Any ideas?

Thanks in advance,
kris