If you use SharePoint template at visual studio 2010, it automaticlly create a .wsp package in the bin fold.
Also I found this article “Using Visual Studio 2010 SharePoint Templates to deploy a web part in SharePoint 2007

Below is some commands from Patrick’s SharePoint Blog

You could include this script in your scripts to be run first, or just include the command that registers the snapin:

Add-PSSnapin Microsoft.SharePoint.PowerShell

Working with Solutions

In the ‘old’ days (let us not forget that the stsadm is still there and we have a lot of SharePoint 2007 installations across the globe), the following stsadm command could be used to add a SharePoint solution to SharePoint:

stsadm –o addsolution –filename “D:\Deploy\MySharePointSolution.wsp“

We used the following command to deploy the solution once installed to a specific web application:

stsadm –o deploysolution –name MySharePointSolution.wsp –url http://myspwebappp –allowgacdeployment –immediate

If we would upgrade an existing solution, we would use the following:

stsadm –o upgradesolution –name MySharePointSolution.wsp –filename “D:\Deploy\MySharePointSolution.wsp” -immediate

And finally, we used the following commands to retract and delete a specific solution from the web application:

stsadm –o retractsolution –name MySharePointSolution.wsp –url http://myspwebapp –immediate
stsadm –o deletesolution –name MySharePointSolution.wsp

Now, let us see how we could do above operations with PowerShell. For this, we use the following PowerShell commands:

Add-SPSolution “D:\Deploy\MySharePointSolution.wsp“
Install-SPSolution –Identity MySharePointSolution.wsp –WebApplication http://myspwebapp –GACDeployment

If you would like to add the solution as sandboxed, you would use the Install-SPUserSolution command instead. To upgrade a solution, we specify which solution is to be updated and with which new solution file:

Update-SPSolution –Identity MySharePointSolution.wsp –LiteralPath “D:\Deploy\MySharePointSolution.wsp” –GacDeployment

To retract and remove a solution, we use the following commands:

Uninstall-SPSolution –Identity MySharePointSolution.wsp –WebApplication http://myspwebapp
Remove-SPSolution–Identity MySharePointSolution.wsp
Working with features

Similarly, commands exist for working with features. The stsadm equivalents:

stsadm –o activatefeature –name MyFeatureName –url http://myspwebapp
stsadm –o deactivatefeature –name MyFeatureName –url http://myspwebapp

Needless to say, there are easy equivalents in PowerShell:

Enable-SPFeature –Identity MyFeatureNameOrGuid –url http://myspwebapp
Disable-SPFeature –Identity MyFeatureNameOrGuid –url http://myspwebapp