Gene ID conversion resources

I see lot of my friends spending time on researching upon databases. There is a dire requirement for compiling all the available databases in a useful and user friendly way. 

Here, let's see the currently available Gene ID conversion resources:

NetAffx: http://www.affymetrix.com/analysis/index.affx

It has batch and net affx query, provides detailed description of individual probeset and allows user to group probsets according to annotation type. Covers 10 species and has 17 possible conversions. 

g:Profiler: http://biit.cs.ut.ee/gprofiler/gconvert.cgi

Input can be a mix of different ID types. User has to choose only the desired output. It covers 31 species and has 14 possible conversions.

Babelomics ID Converter: http://babelomics3.bioinfo.cipf.es/  

GeneID alone as input ID type. Covers 11 species and 36 output ID types are available.

BioDBnet:http://biodbnet.abcc.ncifcrf.gov/db/db2db.php

The most comprehensive and very easy to use database wherein we can give any ID as input and get the output in any convertible ID format.

DAVID: http://david.abcc.ncifcrf.gov/conversion.jsp

User can upload more than one file of different ID types. A specific format is not available and it has 32 possible conversion.

Clone/Gene ID converter:http://idconverter.bioinfo.cnio.es/

Gene ontology, pathway and literature references are available. Provides chromosome location for human. Covers 3 species and has 25 possible conversions.    

The Synergizer: http://llama.mshri.on.ca/synergizer/translate/

It is a repository of gene and protein identifier synonym relationships. The number of species covered changes based on the 'authority' used and accordingly the number of input and output format also change.