This letter is for when you've made a presentation, submitted a proposal or have provided information and you have not received any kind of response. You want to expedite the process without alienating the prospect.
1234, Main Street
Boston, MA 02123
08 April, 2005
<Recipient Address Goes Here>
I haven't heard from you and was wondering if you are still <what you are waiting for>. Since it has been <length of time>, I was wondering if you have any unanswered questions.
<Optional recap of proposal.>
If for some reason you are no longer considering <what was offered>, would you please <desired action>. Of course I hope that is not the case. If I have not heard from you by <deadline> <result>.
I look forward to hearing from you soon.
encl: <List of enclosed items goes here>