The maximum allowable IRA contribution for 2010 is $5,000. However, if you are over age 50, you can make a catch-up IRA contribution of $1,000 for a total contribution of $6,000.
Keep in mind that the IRA limits apply in total to both traditional IRA accounts and Roth IRA accounts. In other words, you can contribute a maximum of $5,000 total to a traditional IRA and a Roth IRA, divided between them any way you like. However, keep in mind that there is an income limit for contributing to a Roth IRA in 2010.
For example, a taxpayer may contribute $3,000 to a Roth IRA and $2,000 to a traditional IRA. This adds up to a total IRA contribution of $5,000 and would be allowable. However, a taxpayer may not contribute $3,000 to a Roth IRA and $3,000 to a regular IRA, because this would add up to $6,000 and exceed the maximum allowable IRA contribution for 2009. However, this would be allowable if the taxpayer were over age 50 because of the catch-up contribution provision.
IRA catch-up contributions may be split across multiple IRAs, but still cannot exceed $1,000 in total.
It is generally easiest to calculate the total allowable IRA contribution and then split that overall amount up in the desired manner.
Further Reading: 2010 401k Contribution Limits