From
http://www.forbes.com/2001/03/06/0306finance.html
Beating Tax Court
Shira J. Boss,
Forbes.com, 03.06.01, 7:00 AM ET
NEW YORK - Last year a writer went to the U.S. Tax Court and argued that he should be able to write off payments to prostitutes as research for a book. The Court ruled that this particular tab was a personal rather than business expense. But the Court did allow him to write off travel expenses for book research, something that the Internal Revenue Service had disallowed.
A commercial airline pilot represented himself in Tax Court after the IRS disallowed a deduction for haircuts and shoe shines.
He lost the point on the haircuts, but the Court ruled that shoe shines were part of the cost of keeping up a uniform, which is a deductible expense.
Also, an excerpt from a search of Federal Tax Cases (this could be the one referenced in the Forbes article, I'm not sure):
MICHAEL C. TOTIN AND DANA E. TOTIN, Petitioners v. COMMISSIONER OF INTERNAL REVENUE, Respondent
Docket No. 9164-83.
UNITED STATES TAX COURT
T.C. Memo 1984-603; 1984 Tax Ct. Memo LEXIS 66; 49 T.C.M. (CCH) 122; T.C.M. (RIA) 84603
November 20, 1984.
[...]
Even if substantiated, the cost of haircuts and razor blades is not deductible. In Fryer v. Commissioner, T.C. Memo. 1974-26, this Court held that the cost of a commercial airline pilot's haircuts was a nondeductible personal expense, even though airline regulations required pilots to have haircuts on a regular basis. Similarly, the cost of the boots is not deductible as they are suitable for personal or private wear. See, e.g., Donnelly v. Commissioner, 262 F.2d 411 (2d. Cir. 1959), affg. 28 T.C. 1278 (1957); Yeomans v. Commissioner, 30 T.C. 757 (1958).