if you need a lawyer is a sure-fire affirmative.

I would get a liar...

I wouldn't mess with the wills in a box if for no other reason than that there are often state law issues that need to be addressed that the box doesn't know about.

It sounds like you need a fairly simple will which shouldn't cost that much.  If you have pre-paid legal, this would be a good time to use it.  I did a bunch of simple wills as an intern through pre-paid and it cost maybe $200 (of course this was a few years ago! :-)  I'd also think about doing a power of attorney and a health care directive (i.e. do not recessitate).

Good luck!

Too young to need a will yet...
but you can use a variety of the online sites that were established by lawyers, etc...
legalzoom.com is the one I always hear.

And the firm I work at has some guys with very strong estate planning practices. I have no will (not married, no kids, just the long time Girl). That said, go see a lawyer. There's a lot more to estate planning than just where your money goes and who gets the kids when you die. Like if you don't die are just horrible injured and lots of other stuff. Just go see a lawyer. Estate planning is the thing most lawyers give flat fees, so you can compare if you're cost conscious.

and for most people the software programs are fine.

And I agree that for most people, the software programs will work just fine.  The only concern I would have (assuming you are doing a very simple will) would be in the execution.  Laws to have a valid will are very specific and if something isn't done right, it can invalidate the whole thing.

Also, if you have a couple of houses and other investments/trusts/stocks/etc., I would just go see an estate lawyer.  They are good at what they do and you don't have to worry about not having something provided for in the will, and thus, not effecuating your intent.

The "common accident" issue is somewhat irrelevant in Texas because in order to be deemed to have outlived your spouse in a common accident, you must survive that spouse by more than 120 hours. I have no idea what you financial situation is, or will be, but if there is any possibility your estate will be in excess of $6 million, go see an attorney (for tax purposes). If not, some of the programs may be adequate, but Texas has pretty specific laws, so make sure it works for Texas (if in fact you live in Texas) and make sure when you execute the docs you have at least 2 witnesses and a notary present. Also, I would advise looking into Powers of Attorney, Medical Powers of Attorney, and Guardianship documents.