Beginner Question: Formatted Text Data -> Hash -> Database.

I have a text document that has formatted data in it, and I am
attempted to determine the best way to parse the data to break it up
into hashes that I can then write to my databases. I suppose my issue
is determining where to tell Ruby to STOP reading in data to write
into the database. The file would be similar to this:

User: Username
Phone: Phone number
Address: Address
Comments: Comments
Data1: Data
Data2: Data
Data3: Data
User: Username
Phone: Phone number
Address: Address
Comments: Comments
Data1: Data
Data2: Data
User: Username
Phone: Phone number
Address: Address
Comments: Comments
Data1: Data
Data2: Data

It's not that difficult to chomp the \n and use a split to create a
hash in a loop, but how do tell Ruby to start a new database write
process if it hits a new "user" key value? Should I write a case
statement to check each line for a "user" key and use that line to
call a new instance of my database class/method? Is there a faster or
more efficient way?

I'll be interested to see what responses you get, but I can't think of a more efficient way. I'd try something like:

my_file.each_line do |line|
  if line ~= /$User/ and this_user.username.length > 0 then
    if this_user.save then
      puts("Saved user #{this_user.username}")
    else
      puts("Problem saving #{this_user.username}!:\n#{this_user.errors}")
    end
    this_user = User.new
  end
  attribute, val = line.split(/:\s*/)
  this_user.send(attribute.lower, val)
end

That's air-code obviously--may be wildly off...