recently, some new ways have been proposed to measure the importance of individual scientists' work or the importance of a publication journal.

The first one is the h-index proposed by physicist J. Hirsch (available also here at the arXiv; See also this Nature news piece). It is defined to be the largest number of publications of an individual scientist that have received at least as many citations. If one has a list of publications, $i$, with their citation numbers, $c(i)$, it is easy to find this number by simply sorting the publications in decreasing number of citations. Now $h$ is equal to $i^*$, where $i^*\leq c(i^*)$ but $i^*+1\geq c(i^*+1)$ and can be easily found by scanning down the list with the naked eye. A relatively easy way to to do this, is to use the Web of Science at the ISI Web of Knowledge. A measure of sustained work is obtained if $h$ is devided by the number of the years over which the papers are published. An average number of 1 is a medium measure. The high numbers range in 1.5–3. My $h$-index is 3, over 2 years so far, which yields a relatively high time-average. But I haven't published in about 2 years, so with my next publication it will halve. (Perhaps I should end my career in its days of glory!) For Nobel Laureate David J Gross this gives an $h$-index of 66 over 40 years, as reported by Nature as well.

The second one is to measure the importance of journals and is more recently proposed by a group of researchers at LANL (See also this Nature news piece). It is based on Google's PageRank (PR) algorithm that determines the ranking of a web page, based not only on the number of links pointing to that page, but also on the number of links the linking pages receive themselves. The common index currently used for publication journals, is the ISI Impact Factor (IF), which measures the number of citations received per publication. PR indicates, the authors say, the prestige of the journal whereas the IF indicates its popularity. Their new measure is called the Y-factor and is a product of IF and PR. It ranks journals more closely to their perceived importance as judjed by the community of researchers; for instance, it places a lower-IF but more commonly thought as prestigious journal, such as Physical Review Letters, higher than the review journal, Reviews of Modern Physics, which ranks higher based solely on IF.