How to name a tag in a list or a data.frame from a string?

Suppose I have a string variable

string='some_string'

Now I want to have a list, where <tag> is the same as the string in
the variable string. I'm wondering if this is possible in R.

list(<tag>=1:3)
data.frame(<tag>=1:3)

The most straightforward way is

x <- list(1:3)
names(x) <- string

y <- data.frame(dummy=1:3)
names(y) <- string

You can also build expressions and parse and evaluate them, but the 
lines above are the easiest way.

Duncan Murdoch