Don’t call your tax preparer (I can't do anything). Go to www.irs.gov and click on Where's My Refund?.
You should have your copy of the 2007 return in front of you when checking on the status of your refund. You will need to enter your Social Security Number, Filing Status (i.e. Single, Head of Household, Married Filing Joint) and the exact amount of the refund as claimed on the return.
You can check on the status of your refund seven days after electronic filing a return. For a paper return you should wait four to six weeks after mailing the return.
The system will advise you if a check has been mailed or if the refund was directly deposited.
You should know that if your refund is directly deposited you will not receive a confirmation from either the IRS or your bank. You must check the bank activity or balance online, or check out a bank statement, to see if the refund was received.
To check on the status of a state income tax refund you should go to the website of the state’s appropriate Finance, Revenue or Taxation department. You can start by going to, for example, www.state.nj.us or www.state.ma.us. Just substitute the "nj" or "ma" with your state's initials.
I expect that once the first round of “stimulus” rebate checks have been mailed out there will be a similar method to check on the status of these checks at www.irs.gov.