I have student loans through both MOHELA and Federal Direct Loans. 
The majority are subsidized, but I have some unsubsidized loans as
well.  I am currently a greaduate student with about two more years to
go and will be taking out additional loans these next two years as
well.  My loans are currently deferred as I am "in school," and I have
never used any of my six month grace period.

Here's my question...  I have heard that now is a good time to
consolidate loans and lock in a low interest rate.  What I need to
know is, is it even possible to consolidate my loans while I am still
in school?  If it is possible, is that a good idea, what are the
benefits/consequences of consolidating loans at this time?

Please let me know if you need any additional clarafication.  Thanks
in advance for any information about this.

Your Financial aid department at school should be able to provide you some advice. 

Here is the info I received from my University, the basic gist is that
you should refinance during your 6 month grace period.

Loan Repayment

Students who borrow a Federal Direct Student Loan and have borrowed a
Federal Stafford Loan in the past, can have their loans consolidated
so that they will be making only one payment. Loan consolidation will
be made at the request of the student when entering repayment. The
university will provide more information to you regarding this option
as you approach graduation.

Loan repayment begins six months after you leave school or cease to be
enrolled an at least a half-time basis. These six months are referred
to as a grace period.

The federal government offers various loan repayment options listed below.


The standard loan repayment plan requires fixed monthly repayment
amount paid over a fixed period of time.
The extended repayment plan assumes a fixed annual repayment amount
paid over an extended period of time.
The graduated repayment plan establishes annual repayment amounts at
two or more levels. Repayments are paid over a fixed or extended
period of time.
The income contingent repayment plan calls for varying annual
repayment amounts based on the Adjusted Gross Income (AGI) of the
borrower over an extended period of time, as determined by the U.S.
Department of Education.
On June 16, 1999 the U.S. Department of Education announced a package
of three discounts for all students who borrow under the Direct Loan
program. The package of discounts includes: 1) a 1% point reduction in
the up-front loan origination fee; from four percent to three percent,
2) a .25% point interest rate deduction for borrowers paying off loans
electronically and 3) a .6% point interest rate deduction for
borrowers who consolidate their loans while they are in school, or
during the six month grace period before they enter repayment.

While you are enrolled in school, no payments are due on the
subsidized Federal Direct Student Loan, and no interest accrues
(unless you are repaying a previous loan and are enrolled less than
full time). The Federal Government pays the interest for you during
this time.

The grace period for the unsubsidized Federal Direct Student Loan is
the same as the subsidized, but you must continue to pay the interest
on the loan while in the grace period. Repayment on the Federal Direct
PLUS Loan begins shortly after the loan is disbursed.