As someone with a lot of student loan debt, I can relate - the first thing you should do is read the promissory note on your current loans - there might be information there you can use. For govt loans (stafford, etc) made after July 1, 2006 the interest rate is going to be fixed and even a federal direct consolidation is not going to lower the rates themselves. If anything, consolidation will just increase the repayment period, which means you'll end up paying more in the long run.
Most private Loans usually offer variable interest rates, which today are quite low. But unless your financial situation is very comfortable and stable, consolidating out of federally guaranteed loans into private loans might not be the best path. You might lose options like deferment, forbearance, and maybe even things like a death benefit (if you die, your loans die with you). related - if you have a co-signer you don't get that death benefit! But refinancing into a variable rate private loan is going to push a lot of risk to you in terms of interest rate inflation, etc. Most financial professionals will agree that interest rates can only go up in the long run.
Keep in mind, student loans are completely unsecured - meaning lenders are taking a fairly large risk in loaning money (and probably why the fed govt has to guarantee most of them).
I've heard of people borrowing against their home equity to pay down student loan debt - but I can't think of a reason you'd want to substitute secured for unsecured debt and possibly lose the loan interest tax deduction.
The bottom line is you're unlikely to find an alternative lending source at a lower interest rate for an unsecured student loan.
Another option may be the income based repayment plan. If you qualify, it caps student loan monthly payments at 15% of your discretionary income (discretionary is your income minus whatever the poverty threshold income amount is). And if that 15% doesn't even cover the interest on the loans, the govt picks up the tab for the difference (for up to 3 years). You have to re-qualify every year by sending in all sorts of documentation, but if you somehow stay on IBR for 25 years, your loans are then forgiven. Obviously the downside here is that you are probably paying little to no principal, but if you do the math and determine that your IBR payment would be next to nothing, and your current situation is barely paying interest-only... well, maybe IBR isn't a bad thing for a couple of years (or 25 if you think you will never have a larger income).
Personally, I went through all these options as well and decided that my best option was to just earn more money... a 2nd job or side project here and there helps me pay down the debt faster, and with less risk, than moving to private variable rate loans.