Silvano,

I have some examples using merge() from my class notes in
http://www.leg.ufpr.br/doku.php/disciplinas:ce223-2011-01. See "aula11.R".
For the moment, this minimal reproducible code can be useful

id <- 1:30
n <- 20

a1 <- data.frame(id=sample(id, n), v1=rnorm(n))
a2 <- data.frame(id=sample(id, n), v2=rpois(n,10))
a3 <- data.frame(id=sample(id, n), v3=runif(n))

merge(a1, a2, by="id") # just two data.frame at once

a0 <- list(a1, a2, a3)

Reduce(function(x, y) merge(x, y, by="id"), a0, accumulate=FALSE)
# font: http://rwiki.sciviews.org/doku.php?id=tips:data-frames:merge

You can also join to the R-br mailing list (brazilian R-help list).
Instructions in http://www.leg.ufpr.br/doku.php/software:rbr

Bests.
Walmes.

==========================================================================
Walmes Marques Zeviani
LEG (Laboratório de Estatística e Geoinformação, 25.450418 S, 49.231759 W)
Departamento de Estatística - Universidade Federal do Paraná
fone: (+55) 41 3361 3573
VoIP: (3361 3600) 1053 1173
e-mail: walmes@ufpr.br
twitter: @walmeszeviani
homepage: http://www.leg.ufpr.br/~walmes
linux user number: 531218
==========================================================================

	[[alternative HTML version deleted]]

