The question is a little broad but for what it's worth...

Let's look at some options for cash...

Money Market Mutual Funds
Bank CD's
Internet Banks
Treasury Bills
Tax Exempt Money Market Funds
and of course the traditional Bank savings account

Money Market Mutual Funds
Extremely safe as they invest primarily in large bank certificates, commercial loans (short term corporate loans) and government securities.

Options:
Fidelity Spartan Money Market Fund
TIAA-CREF Money Market Fund
USAA Money Market Fund
Vanguard Money Market Fund

Bank CD's
Supra safe but they won't have access to it without penalty for the duration of the CD. You can get CD's from just about any bank and they'll typically come in 3, 6 month varieties as well as 1, 3, and 5 years. The longer the peiod the more the interest so this will depend on when they think they'll be making a decision. They're also FDIC insured but if they're extremely concerned I wouldn't put more than $80-$90k in each account so the $100k insurance covers them.

Internet Banks
The nice thing about Internet banks is they don't have the overhead of brick and mortar banks (e.g. BofA, Wells, etc.) so they can offer slightly higher interest rates. Make sure these are FDIC insured though since the risk is just a tad bit higher. Same rule would apply as for Bank CD's if they're extremely conservative.

Options
NetBank
VirtualBank
ING

Treasury Bills
Did I say supra safe before? Supra-dupra safe here. You can get these in 4 week, 3 month, 6 month increments and longer. The extra bonus is they're exempt from taxes...

Go to www.treasurydirect.gov for more info.

Tax-Exempt Money Market Funds
Pretty darn safe too and if they're in a high income tax bracket a good alternative.

Option
Fidelity Muni Money Market Fund
USAA Tax Exempt money market fund
Vanguard tax-exempt money market fund

It's really up to them and how conservative they want to be...any of the above options are very, very safe so I don't see that they could go wrong. Seems like a financial planner is a good idea and they may even want to try Motley Fools Premium subscription (http://www.fool.com/ma/index.htm?ref=topnav) for $200. There's actually a 30 day trial period that will allow them access to the boards and to a hotline that can give them additional advice depending on where they're wanting to go.

Best of luck...

Jesse